diff --git a/app/include/MainWindow.h b/app/include/MainWindow.h
index 77c6b09..d16d4f5 100644
--- a/app/include/MainWindow.h
+++ b/app/include/MainWindow.h
@@ -52,6 +52,7 @@ public slots:
 
 protected:
     void changeEvent(QEvent *e);
+    void closeEvent(QCloseEvent *event);
 
 private:
     std::unique_ptr<Ui::MainWindow> m_Ui;
diff --git a/app/src/MainWindow.cpp b/app/src/MainWindow.cpp
index eda17cd..02ff19c 100644
--- a/app/src/MainWindow.cpp
+++ b/app/src/MainWindow.cpp
@@ -22,6 +22,7 @@
 #include "MainWindow.h"
 #include "ui_MainWindow.h"
 
+#include <Catalogue/CatalogueController.h>
 #include <Catalogue/CatalogueExplorer.h>
 #include <DataSource/DataSourceController.h>
 #include <DataSource/DataSourceWidget.h>
@@ -36,9 +37,11 @@
 #include <Visualization/VisualizationController.h>
 
 #include <QAction>
+#include <QCloseEvent>
 #include <QDate>
 #include <QDir>
 #include <QFileDialog>
+#include <QMessageBox>
 #include <QToolBar>
 #include <QToolButton>
 #include <memory.h>
@@ -74,6 +77,8 @@ public:
     SqpSettingsDialog *m_SettingsDialog;
     /// Catalogue dialog. MainWindow has the ownership
     CatalogueExplorer *m_CatalogExplorer;
+
+    bool checkDataToSave(QWidget *parentWidget);
 };
 
 MainWindow::MainWindow(QWidget *parent)
@@ -364,3 +369,37 @@ void MainWindow::changeEvent(QEvent *e)
             break;
     }
 }
+
+void MainWindow::closeEvent(QCloseEvent *event)
+{
+    if (!impl->checkDataToSave(this)) {
+        event->ignore();
+    }
+    else {
+        event->accept();
+    }
+}
+
+bool MainWindow::MainWindowPrivate::checkDataToSave(QWidget *parentWidget)
+{
+    auto hasChanges = sqpApp->catalogueController().hasChanges();
+    if (hasChanges) {
+        // There are some unsaved changes
+        switch (QMessageBox::question(
+            parentWidget, "Save changes",
+            tr("The catalogue controller unsaved changes.\nDo you want to save them ?"),
+            QMessageBox::SaveAll | QMessageBox::Discard | QMessageBox::Cancel,
+            QMessageBox::SaveAll)) {
+            case QMessageBox::SaveAll:
+                sqpApp->catalogueController().saveAll();
+                break;
+            case QMessageBox::Discard:
+                break;
+            case QMessageBox::Cancel:
+            default:
+                return false;
+        }
+    }
+
+    return true;
+}
diff --git a/core/include/Catalogue/CatalogueController.h b/core/include/Catalogue/CatalogueController.h
index b9b2835..4a2007f 100644
--- a/core/include/Catalogue/CatalogueController.h
+++ b/core/include/Catalogue/CatalogueController.h
@@ -62,6 +62,7 @@ public:
     void saveCatalogue(std::shared_ptr<DBCatalogue> catalogue);
 
     void saveAll();
+    bool hasChanges() const;
 
     /// Returns the MIME data associated to a list of variables
     QByteArray mimeDataForEvents(const QVector<std::shared_ptr<DBEvent> > &events) const;
diff --git a/core/src/Catalogue/CatalogueController.cpp b/core/src/Catalogue/CatalogueController.cpp
index b2892b7..653d975 100644
--- a/core/src/Catalogue/CatalogueController.cpp
+++ b/core/src/Catalogue/CatalogueController.cpp
@@ -249,6 +249,11 @@ void CatalogueController::saveAll()
     impl->m_EventKeysWithChanges.clear();
 }
 
+bool CatalogueController::hasChanges() const
+{
+    return !impl->m_EventKeysWithChanges.isEmpty(); // TODO: catalogues
+}
+
 QByteArray
 CatalogueController::mimeDataForEvents(const QVector<std::shared_ptr<DBEvent> > &events) const
 {