diff --git a/public/index.php b/public/index.php
index 97d84a0..9a174e2 100644
--- a/public/index.php
+++ b/public/index.php
@@ -107,6 +107,7 @@ $router->post('/logout', fn($p) => (new LoginController())->handleLogout($p));
 // ── Benutzerverwaltung ────────────────────────────────────────
 $router->get('/useradmin', fn($p) => (new UserAdminController())->index($p));
 $router->post('/useradmin', fn($p) => (new UserAdminController())->store($p));
+$router->post('/useradmin/{id}',        fn($p) => (new UserAdminController())->update($p));
 $router->post('/useradmin/{id}/delete', fn($p) => (new UserAdminController())->delete($p));
 $router->post('/useradmin/{id}/toggle', fn($p) => (new UserAdminController())->toggleActive($p));
 
diff --git a/src/Controllers/UserAdminController.php b/src/Controllers/UserAdminController.php
index 3ac80bd..a44072d 100644
--- a/src/Controllers/UserAdminController.php
+++ b/src/Controllers/UserAdminController.php
@@ -57,6 +57,50 @@ class UserAdminController
         View::redirect('/useradmin', 'Benutzer angelegt.');
     }
 
+    public function update(array $params): void
+    {
+        $id       = (int)($params['id'] ?? 0);
+        $username = trim($_POST['username'] ?? '');
+        $password = $_POST['password'] ?? '';
+        $errors   = [];
+
+        if (!User::find($id)) {
+            View::redirect('/useradmin', 'Benutzer nicht gefunden.', 'error');
+            return;
+        }
+
+        if ($username === '') {
+            $errors['username'] = 'Pflichtfeld';
+        } elseif (strlen($username) > 64) {
+            $errors['username'] = 'Maximal 64 Zeichen';
+        } else {
+            $existing = User::findByUsername($username);
+            if ($existing && (int)$existing['id'] !== $id) {
+                $errors['username'] = 'Benutzername bereits vergeben';
+            }
+        }
+
+        if ($password !== '' && strlen($password) < 8) {
+            $errors['password'] = 'Mindestens 8 Zeichen erforderlich';
+        }
+
+        if ($errors) {
+            $view = new View();
+            $view->render('layout/base.php', [
+                'pageTitle' => 'Benutzerverwaltung',
+                'content'   => $this->renderView('useradmin/list', [
+                    'users'    => User::all(),
+                    'errors'   => $errors,
+                    'formData' => ['username' => $username, 'edit_id' => $id],
+                ]),
+            ]);
+            return;
+        }
+
+        User::update($id, $username, $password);
+        View::redirect('/useradmin', 'Benutzer gespeichert.');
+    }
+
     public function delete(array $params): void
     {
         $id = (int)($params['id'] ?? 0);
diff --git a/src/Models/User.php b/src/Models/User.php
index 0e45d41..efad6b0 100644
--- a/src/Models/User.php
+++ b/src/Models/User.php
@@ -45,6 +45,22 @@ class User
         Database::execute('DELETE FROM users WHERE id = ?', [$id]);
     }
 
+    public static function update(int $id, string $username, string $password = ''): void
+    {
+        if ($password !== '') {
+            $hash = password_hash($password, PASSWORD_BCRYPT);
+            Database::execute(
+                'UPDATE users SET username = ?, password_hash = ? WHERE id = ?',
+                [$username, $hash, $id]
+            );
+        } else {
+            Database::execute(
+                'UPDATE users SET username = ? WHERE id = ?',
+                [$username, $id]
+            );
+        }
+    }
+
     public static function setActive(int $id, bool $active): void
     {
         Database::execute(
diff --git a/src/Views/useradmin/list.php b/src/Views/useradmin/list.php
index 4e1a61c..019e95a 100644
--- a/src/Views/useradmin/list.php
+++ b/src/Views/useradmin/list.php
@@ -1,13 +1,16 @@
-<?php use Steuerkram\View; $h = fn($v) => View::h($v); ?>
+<?php use Steuerkram\View; $h = fn($v) => View::h($v);
+$editId = $formData['edit_id'] ?? null;
+?>
 
 <div class="card" style="margin-bottom:1.5rem;">
-    <div class="card-header"><div class="card-title">Neuen Benutzer anlegen</div></div>
+    <div class="card-header"><div class="card-title" id="form-title"><?= $editId ? 'Benutzer bearbeiten' : 'Neuen Benutzer anlegen' ?></div></div>
     <div class="card-body">
-        <form method="POST" action="/useradmin">
+        <form method="POST" id="user-form"
+              action="<?= $editId ? '/useradmin/' . (int)$editId : '/useradmin' ?>">
             <div class="form-row">
                 <div class="form-group" style="flex:1">
                     <label>Benutzername</label>
-                    <input type="text" name="username"
+                    <input type="text" id="field-username" name="username"
                            value="<?= $h($formData['username'] ?? '') ?>"
                            class="<?= isset($errors['username']) ? 'input-error' : '' ?>"
                            maxlength="64" required>
@@ -16,16 +19,22 @@
                     <?php endif; ?>
                 </div>
                 <div class="form-group" style="flex:1">
-                    <label>Passwort</label>
-                    <input type="password" name="password"
+                    <label id="password-label"><?= $editId ? 'Neues Passwort (leer lassen = unverändert)' : 'Passwort' ?></label>
+                    <input type="password" id="field-password" name="password"
                            class="<?= isset($errors['password']) ? 'input-error' : '' ?>"
-                           autocomplete="new-password" required>
+                           autocomplete="new-password"
+                           <?= $editId ? '' : 'required' ?>>
                     <?php if (isset($errors['password'])): ?>
                         <div class="error-text"><?= $h($errors['password']) ?></div>
                     <?php endif; ?>
                 </div>
-                <div style="padding-bottom:.05rem">
-                    <button type="submit" class="btn btn-primary">Anlegen</button>
+                <div style="display:flex;gap:.5rem;align-items:flex-end;padding-bottom:.05rem">
+                    <button type="submit" id="submit-btn" class="btn btn-primary">
+                        <?= $editId ? 'Speichern' : 'Anlegen' ?>
+                    </button>
+                    <button type="button" id="cancel-btn" class="btn btn-secondary"
+                            style="<?= $editId ? '' : 'display:none' ?>"
+                            onclick="resetForm()">Abbrechen</button>
                 </div>
             </div>
         </form>
@@ -59,6 +68,10 @@
                         </td>
                         <td><?= $h(View::formatDate(substr($u['created_at'], 0, 10))) ?></td>
                         <td style="text-align:right">
+                            <button type="button" class="btn btn-sm btn-secondary"
+                                    onclick="editUser(<?= (int)$u['id'] ?>, <?= $h(json_encode($u['username'])) ?>)">
+                                Bearbeiten
+                            </button>
                             <form method="POST" action="/useradmin/<?= (int)$u['id'] ?>/toggle" style="display:inline;">
                                 <button type="submit" class="btn btn-sm <?= $u['active'] ? 'btn-secondary' : 'btn-primary' ?>">
                                     <?= $u['active'] ? 'Deaktivieren' : 'Aktivieren' ?>
@@ -75,3 +88,29 @@
         </table>
     <?php endif; ?>
 </div>
+
+<script>
+function editUser(id, username) {
+    document.getElementById('field-username').value = username;
+    document.getElementById('field-password').value = '';
+    document.getElementById('field-password').removeAttribute('required');
+    document.getElementById('user-form').action = '/useradmin/' + id;
+    document.getElementById('form-title').textContent = 'Benutzer bearbeiten';
+    document.getElementById('password-label').textContent = 'Neues Passwort (leer lassen = unverändert)';
+    document.getElementById('submit-btn').textContent = 'Speichern';
+    document.getElementById('cancel-btn').style.display = '';
+    document.getElementById('field-username').focus();
+    document.querySelector('.card').scrollIntoView({behavior: 'smooth'});
+}
+
+function resetForm() {
+    document.getElementById('field-username').value = '';
+    document.getElementById('field-password').value = '';
+    document.getElementById('field-password').setAttribute('required', '');
+    document.getElementById('user-form').action = '/useradmin';
+    document.getElementById('form-title').textContent = 'Neuen Benutzer anlegen';
+    document.getElementById('password-label').textContent = 'Passwort';
+    document.getElementById('submit-btn').textContent = 'Anlegen';
+    document.getElementById('cancel-btn').style.display = 'none';
+}
+</script>