diff --git a/content/showArticle.php b/content/showArticle.php
index 1dc42f4..c5152c1 100644
--- a/content/showArticle.php
+++ b/content/showArticle.php
@@ -193,6 +193,47 @@ if ($replyAuthor === null) {
                                     isset($_SESSION["user_email"])
                                     && $_SESSION["user_email"] === $comment->getAuthor()
                             ): ?>
+                                <details class="edit-comment-details">
+                                    <summary class="edit-comment-button">
+                                        Kommentar bearbeiten
+                                    </summary>
+
+                                    <form method="post"
+                                          action="index.php?pfad=updateComment"
+                                          class="edit-comment-form">
+
+                                        <input type="hidden"
+                                               name="comment_id"
+                                               value="<?php echo htmlspecialchars(
+                                                       (string) $comment->getId()
+                                               ); ?>">
+
+                                        <input type="hidden"
+                                               name="article_id"
+                                               value="<?php echo htmlspecialchars(
+                                                       (string) $comment->getArticleId()
+                                               ); ?>">
+
+                                        <label for="edit-comment-<?php
+                                        echo htmlspecialchars((string) $comment->getId());
+                                        ?>">
+                                            Kommentar bearbeiten
+                                        </label>
+
+                                        <textarea
+                                                id="edit-comment-<?php
+                                                echo htmlspecialchars((string) $comment->getId());
+                                                ?>"
+                                                name="content"
+                                                required><?php echo htmlspecialchars(
+                                                    $comment->getContent()
+                                            ); ?></textarea>
+
+                                        <button type="submit" class="button">
+                                            Änderungen speichern
+                                        </button>
+                                    </form>
+                                </details>
 
                                 <form method="post"
                                       action="index.php?pfad=deleteComment"
@@ -267,8 +308,8 @@ if ($replyAuthor === null) {
                                                 </strong>
 
                                                 <span>
-                <?php echo htmlspecialchars($reply->getCreated()); ?>
-            </span>
+                    <?php echo htmlspecialchars($reply->getCreated()); ?>
+                </span>
                                             </p>
 
                                             <p>
@@ -284,6 +325,48 @@ if ($replyAuthor === null) {
                                                     && $_SESSION["user_email"] === $reply->getAuthor()
                                             ): ?>
 
+                                                <details class="edit-comment-details">
+                                                    <summary class="edit-comment-button">
+                                                        Antwort bearbeiten
+                                                    </summary>
+
+                                                    <form method="post"
+                                                          action="index.php?pfad=updateComment"
+                                                          class="edit-comment-form">
+
+                                                        <input type="hidden"
+                                                               name="comment_id"
+                                                               value="<?php echo htmlspecialchars(
+                                                                       (string) $reply->getId()
+                                                               ); ?>">
+
+                                                        <input type="hidden"
+                                                               name="article_id"
+                                                               value="<?php echo htmlspecialchars(
+                                                                       (string) $reply->getArticleId()
+                                                               ); ?>">
+
+                                                        <label for="edit-reply-<?php
+                                                        echo htmlspecialchars((string) $reply->getId());
+                                                        ?>">
+                                                            Antwort bearbeiten
+                                                        </label>
+
+                                                        <textarea
+                                                                id="edit-reply-<?php
+                                                                echo htmlspecialchars((string) $reply->getId());
+                                                                ?>"
+                                                                name="content"
+                                                                required><?php echo htmlspecialchars(
+                                                                    $reply->getContent()
+                                                            ); ?></textarea>
+
+                                                        <button type="submit" class="button">
+                                                            Änderungen speichern
+                                                        </button>
+                                                    </form>
+                                                </details>
+
                                                 <form method="post"
                                                       action="index.php?pfad=deleteComment"
                                                       class="delete-comment-form">
diff --git a/index.php b/index.php
index 3fc2548..91515f7 100644
--- a/index.php
+++ b/index.php
@@ -39,8 +39,8 @@ if ($pfad === "deleteAccount") {
     include_once "php/controller/deleteAccount-controller.php";
     exit();
 }
-if ($pfad === "deleteComment") {
-    include_once "php/controller/deleteComment-controller.php";
+if ($pfad === "updateComment") {
+    include_once "php/controller/updateComment-controller.php";
     exit();
 }
 ?>
diff --git a/php/controller/updateComment-controller.php b/php/controller/updateComment-controller.php
new file mode 100644
index 0000000..e215911
--- /dev/null
+++ b/php/controller/updateComment-controller.php
@@ -0,0 +1,92 @@
+<?php
+
+if (session_status() === PHP_SESSION_NONE) {
+    session_start();
+}
+
+require_once "php/model/CommentManager.php";
+
+if ($_SERVER["REQUEST_METHOD"] !== "POST") {
+    header("Location: index.php");
+    exit();
+}
+
+if (!isset($_SESSION["user_email"])) {
+    header("Location: index.php?pfad=login");
+    exit();
+}
+
+$commentId = filter_input(
+    INPUT_POST,
+    "comment_id",
+    FILTER_VALIDATE_INT
+);
+
+$articleId = filter_input(
+    INPUT_POST,
+    "article_id",
+    FILTER_VALIDATE_INT
+);
+
+$content = trim($_POST["content"] ?? "");
+
+/*
+ * Ohne gültige Beitrags-ID kann nicht sicher
+ * zum ursprünglichen Beitrag zurückgeleitet werden.
+ */
+if (!$articleId) {
+    header("Location: index.php");
+    exit();
+}
+
+/*
+ * Kommentar-ID und Inhalt werden geprüft.
+ */
+if (!$commentId || $content === "") {
+    $_SESSION["comment_message"] =
+        "Der Kommentar darf nicht leer sein.";
+
+    $_SESSION["comment_message_type"] = "error";
+
+    header(
+        "Location: index.php?pfad=showArticle&id="
+        . urlencode((string) $articleId)
+        . "#comments"
+    );
+    exit();
+}
+
+try {
+    $commentManager = CommentManager::getInstance();
+
+    $updated = $commentManager->updateComment(
+        $commentId,
+        $_SESSION["user_email"],
+        $content
+    );
+
+    if ($updated) {
+        $_SESSION["comment_message"] =
+            "Der Kommentar wurde erfolgreich bearbeitet.";
+
+        $_SESSION["comment_message_type"] = "success";
+    } else {
+        $_SESSION["comment_message"] =
+            "Der Kommentar konnte nicht bearbeitet werden.";
+
+        $_SESSION["comment_message_type"] = "error";
+    }
+
+} catch (Throwable $e) {
+    $_SESSION["comment_message"] =
+        "Beim Bearbeiten des Kommentars ist ein Fehler aufgetreten.";
+
+    $_SESSION["comment_message_type"] = "error";
+}
+
+header(
+    "Location: index.php?pfad=showArticle&id="
+    . urlencode((string) $articleId)
+    . "#comments"
+);
+exit();
diff --git a/php/model/CommentManagerDAO.php b/php/model/CommentManagerDAO.php
index 1390815..518d819 100644
--- a/php/model/CommentManagerDAO.php
+++ b/php/model/CommentManagerDAO.php
@@ -72,4 +72,19 @@ interface CommentManagerDAO
      * @return void
      */
     public function deleteCommentsByAuthor(string $author): void;
+    /**
+     * Bearbeitet einen Kommentar des angemeldeten Nutzers.
+     *
+     * Nur der Autor des Kommentars darf den Inhalt ändern.
+     *
+     * @param int $commentId ID des Kommentars
+     * @param string $author E-Mail-Adresse des Autors
+     * @param string $content Neuer Kommentarinhalt
+     * @return bool true, wenn der Kommentar bearbeitet wurde
+     */
+    public function updateComment(
+        int $commentId,
+        string $author,
+        string $content
+    ): bool;
 }
\ No newline at end of file
diff --git a/php/model/DatabaseCommentManager.php b/php/model/DatabaseCommentManager.php
index 31bea09..ab9e5aa 100644
--- a/php/model/DatabaseCommentManager.php
+++ b/php/model/DatabaseCommentManager.php
@@ -223,6 +223,44 @@ class DatabaseCommentManager implements CommentManagerDAO
 
         return $comments;
     }
+    /**
+     * Bearbeitet einen eigenen Kommentar.
+     *
+     * Der Kommentar wird nur geändert, wenn er dem
+     * angemeldeten Nutzer gehört.
+     *
+     * @param int $commentId ID des Kommentars
+     * @param string $author E-Mail-Adresse des Autors
+     * @param string $content Neuer Kommentarinhalt
+     * @return bool true, wenn der Kommentar bearbeitet wurde
+     */
+    public function updateComment(
+        int $commentId,
+        string $author,
+        string $content
+    ): bool {
+        try {
+            $db = $this->getConnection();
+
+            $command = $db->prepare("
+            UPDATE comments
+            SET content = :content
+            WHERE id = :commentId
+              AND author = :author
+        ");
+
+            $command->execute([
+                ":content" => $content,
+                ":commentId" => $commentId,
+                ":author" => $author
+            ]);
+
+            return $command->rowCount() > 0;
+
+        } catch (PDOException $e) {
+            throw new RuntimeException("internal_error");
+        }
+    }
     /**
      * Löscht einen eigenen Kommentar.
      *