diff --git a/pages/index.html b/pages/index.html
index 55e8abd..2ab31e7 100644
--- a/pages/index.html
+++ b/pages/index.html
@@ -59,7 +59,11 @@ document.addEventListener('DOMContentLoaded', async function() {
     if (response.ok && todosJson != null) {
         let todosDiv = document.getElementById("todos");
         todosJson.forEach((item) => {
-            console.log(item);
+            // Do not work with completed TODOs yet
+            if (item.isDone == true) {
+                return;
+            }
+
             todos.push(item);
             let todoCompleteBtnID = "btn-complete-" + String(item.id);
 
diff --git a/src/db/db.go b/src/db/db.go
index bd4cbe1..166477a 100644
--- a/src/db/db.go
+++ b/src/db/db.go
@@ -61,6 +61,8 @@ func setUpTables(db *DB) error {
 		time_created_unix INTEGER,
 		due_unix INTEGER,
 		owner_username TEXT NOT NULL,
+		is_done INTEGER,
+		completion_time_unix INTEGER,
 		FOREIGN KEY(group_id) REFERENCES todo_groups(id),
 		FOREIGN KEY(owner_username) REFERENCES users(username))`,
 	)
diff --git a/src/db/todo.go b/src/db/todo.go
index 42f2264..6ef858c 100644
--- a/src/db/todo.go
+++ b/src/db/todo.go
@@ -30,12 +30,14 @@ type TodoGroup struct {
 
 // Todo structure
 type Todo struct {
-	ID              uint64 `json:"id"`
-	GroupID         uint64 `json:"groupId"`
-	Text            string `json:"text"`
-	TimeCreatedUnix uint64 `json:"timeCreatedUnix"`
-	DueUnix         uint64 `json:"dueUnix"`
-	OwnerUsername   string `json:"ownerUsername"`
+	ID                 uint64 `json:"id"`
+	GroupID            uint64 `json:"groupId"`
+	Text               string `json:"text"`
+	TimeCreatedUnix    uint64 `json:"timeCreatedUnix"`
+	DueUnix            uint64 `json:"dueUnix"`
+	OwnerUsername      string `json:"ownerUsername"`
+	IsDone             bool   `json:"isDone"`
+	CompletionTimeUnix uint64 `json:"completionTimeUnix"`
 }
 
 // Creates a new TODO group in the database
@@ -136,6 +138,8 @@ func scanTodo(rows *sql.Rows) (*Todo, error) {
 		&newTodo.TimeCreatedUnix,
 		&newTodo.DueUnix,
 		&newTodo.OwnerUsername,
+		&newTodo.IsDone,
+		&newTodo.CompletionTimeUnix,
 	)
 	if err != nil {
 		return nil, err
@@ -188,12 +192,14 @@ func (db *DB) GetTodos() ([]*Todo, error) {
 // Creates a new TODO in the database
 func (db *DB) CreateTodo(todo Todo) error {
 	_, err := db.Exec(
-		"INSERT INTO todos(group_id, text, time_created_unix, due_unix, owner_username) VALUES(?, ?, ?, ?, ?)",
+		"INSERT INTO todos(group_id, text, time_created_unix, due_unix, owner_username, is_done, completion_time_unix) VALUES(?, ?, ?, ?, ?, ?, ?)",
 		todo.GroupID,
 		todo.Text,
 		todo.TimeCreatedUnix,
 		todo.DueUnix,
 		todo.OwnerUsername,
+		todo.IsDone,
+		todo.CompletionTimeUnix,
 	)
 
 	return err
@@ -209,13 +215,15 @@ func (db *DB) DeleteTodo(id uint64) error {
 	return err
 }
 
-// Updates TODO's due date, text and group id
+// Updates TODO's due date, text, done state, completion time and group id
 func (db *DB) UpdateTodo(todoID uint64, updatedTodo Todo) error {
 	_, err := db.Exec(
-		"UPDATE todos SET group_id=?, due_unix=?, text=?  WHERE id=?",
+		"UPDATE todos SET group_id=?, due_unix=?, text=?, is_done=?, completion_time_unix=?  WHERE id=?",
 		updatedTodo.GroupID,
 		updatedTodo.DueUnix,
 		updatedTodo.Text,
+		updatedTodo.IsDone,
+		updatedTodo.CompletionTimeUnix,
 		todoID,
 	)
 
diff --git a/src/server/api.go b/src/server/api.go
index c03d50e..725fc96 100644
--- a/src/server/api.go
+++ b/src/server/api.go
@@ -150,16 +150,33 @@ func (s *Server) TodoEndpoint(w http.ResponseWriter, req *http.Request) {
 			return
 		}
 
-		// Now delete
-		err = s.db.DeleteTodo(todoID)
+		// Mark TODO as done and assign a completion time
+		updatedTodo, err := s.db.GetTodo(todoID)
 		if err != nil {
-			logger.Error("[Server] Failed to delete %s's TODO: %s", GetUsernameFromAuth(req), err)
-			http.Error(w, "Failed to delete TODO", http.StatusInternalServerError)
+			logger.Error("[Server] Failed to get todo with id %d for marking completion: %s", todoID, err)
+			http.Error(w, "TODO retrieval error", http.StatusInternalServerError)
 			return
 		}
+		updatedTodo.IsDone = true
+		updatedTodo.CompletionTimeUnix = uint64(time.Now().Unix())
+
+		err = s.db.UpdateTodo(todoID, *updatedTodo)
+		if err != nil {
+			logger.Error("[Server] Failed to update TODO with id %d: %s", todoID, err)
+			http.Error(w, "Failed to update TODO information", http.StatusInternalServerError)
+			return
+		}
+
+		// Now delete
+		// err = s.db.DeleteTodo(todoID)
+		// if err != nil {
+		// 	logger.Error("[Server] Failed to delete %s's TODO: %s", GetUsernameFromAuth(req), err)
+		// 	http.Error(w, "Failed to delete TODO", http.StatusInternalServerError)
+		// 	return
+		// }
 
 		// Success!
-		logger.Info("[Server] deleted TODO with ID %d", todoID)
+		logger.Info("[Server] updated (marked as done) TODO with ID %d", todoID)
 		w.WriteHeader(http.StatusOK)
 
 	case http.MethodPost: