diff --git a/lumi2/templates/usermanager/group_edit.html b/lumi2/templates/usermanager/group_edit.html
new file mode 100644
index 0000000..02a6832
--- /dev/null
+++ b/lumi2/templates/usermanager/group_edit.html
@@ -0,0 +1,46 @@
+{% extends 'base.html' %}
+
+{% block content %}
+<div class="row">
+    <div class="col">
+        <h1>Editing group: {{ group.groupname }}</h1>
+    </div>
+</div>
+<form method="post">
+    {{ form.csrf_token }}
+    <div class="row mb-3">
+        <div class="col-sm">
+            {{ form.members.label(class="form-label") }}
+            {{ form.members(class="form-control" + (" is-invalid" if form.members.errors else "")) }}
+            {% if form.members.errors %}
+            {% for error in form.members.errors %}
+            <div class="invalid-feedback">{{ error }}</div>
+            {% endfor %}
+            {% endif %}
+            <div id="membersHelp" class="form-text">
+                List of members of this group.
+            </div>
+        </div>
+        <div class="col-sm">
+            {{ form.non_members.label(class="form-label") }}
+            {{ form.non_members(class="form-control" + (" is-invalid" if form.non_members.errors else "")) }}
+            {% if form.non_members.errors %}
+            {% for error in form.non_members.errors %}
+            <div class="invalid-feedback">{{ error }}</div>
+            {% endfor %}
+            {% endif %}
+            <div id="non_membersHelp" class="form-text">
+                List of users who are not members of this group.
+            </div>
+        </div>
+    </div>
+    <div class="row mb-3">
+        <div class="col-sm">
+            <a class="btn btn-secondary"
+                href="#"
+                role="button">Reset</a>
+            {{ form.submit(class_="btn btn-primary") }}
+        </div>
+    </div>
+</form>
+{% endblock content %}
diff --git a/lumi2/usermanager.py b/lumi2/usermanager.py
index 9ea6782..8bbef5f 100644
--- a/lumi2/usermanager.py
+++ b/lumi2/usermanager.py
@@ -9,7 +9,7 @@ from flask import (
 from PIL import Image, UnidentifiedImageError
 from flask_wtf import FlaskForm
 from flask_wtf.file import FileField, FileAllowed
-from wtforms import ValidationError, StringField, PasswordField, SubmitField
+from wtforms import ValidationError, StringField, PasswordField, SubmitField, SelectMultipleField
 from wtforms.validators import InputRequired, Email, EqualTo
 
 import lumi2.ldap as ldap
@@ -300,3 +300,50 @@ def user_delete(username: str):
         username=user.username,
         deleted_groups=deleted_groups,
     )
+
+
+class GroupUpdateForm(FlaskForm):
+    members = SelectMultipleField(
+        'Group members',
+        validators=[InputRequired()],
+    )
+
+    non_members = SelectMultipleField(
+        'Other users',
+    )
+
+    submit = SubmitField(
+        'Update',
+    )
+
+
+@bp.route("/groups/update/<string:groupname>")
+def group_update(groupname: str):
+    """Detail and Update view for a group.
+
+    Shows a form allowing the modification of user memberships for this group.
+    """
+
+    try:
+        conn = ldap.get_connection()
+    except Exception:
+        abort(500)
+
+    try:
+        group = ldap.get_group(conn, groupname)
+    except ldap.EntryNotFoundException:
+        conn.unbind()
+        abort(404)
+
+    form = GroupUpdateForm()
+    form.members.choices = sorted({user.username for user in group.members})
+    form.non_members.choices = sorted(
+        {user.username for user in ldap.get_users(conn)} - set(form.members.choices)
+    )
+
+    conn.unbind()
+    return render_template(
+        'usermanager/group_edit.html',
+        form=form,
+        group=group,
+    )