diff --git a/AABB_tree/demo/AABB_tree/Scene.cpp b/AABB_tree/demo/AABB_tree/Scene.cpp
index bb332daedb5..53fba8fe327 100644
--- a/AABB_tree/demo/AABB_tree/Scene.cpp
+++ b/AABB_tree/demo/AABB_tree/Scene.cpp
@@ -1310,7 +1310,7 @@ void Scene::deactivate_cutting_plane()
     disconnect(m_frame, SIGNAL(modified()), this, SLOT(cutting_plane()));
     m_view_plane = false;
 }
-void Scene::initGL(Viewer *viewer)
+void Scene::initGL(Viewer */* viewer */)
 {
     //qDebug()<<"context from scene is valid :"<<context->isValid();
     //gl = 0;
diff --git a/Kinetic_data_structures/include/CGAL/Kinetic/IO/Qt_widget_2.h b/Kinetic_data_structures/include/CGAL/Kinetic/IO/Qt_widget_2.h
index 689799dbaf7..5ad964c54b4 100644
--- a/Kinetic_data_structures/include/CGAL/Kinetic/IO/Qt_widget_2.h
+++ b/Kinetic_data_structures/include/CGAL/Kinetic/IO/Qt_widget_2.h
@@ -237,10 +237,10 @@ private:
   }
 
  
-  This operator=(const This &o) {
+  This operator=(const This &/* o */) {
     return *this;
   }
-  Qt_widget_2(const This &o){}
+  Qt_widget_2(const This &/* o */){}
 protected:
   std::auto_ptr<QApplication> app_;
   typename Graphical_base::Handle base_;
diff --git a/Mesh_3/demo/Mesh_3/C3t3_rib_exporter_plugin.cpp b/Mesh_3/demo/Mesh_3/C3t3_rib_exporter_plugin.cpp
index 6881495f62c..41db2b47a00 100644
--- a/Mesh_3/demo/Mesh_3/C3t3_rib_exporter_plugin.cpp
+++ b/Mesh_3/demo/Mesh_3/C3t3_rib_exporter_plugin.cpp
@@ -714,7 +714,7 @@ write_facets(const C3t3& c3t3, const Plane& plane, std::ofstream& out)
 
 void
 C3t3_rib_exporter_plugin::
-write_surface_cells(const C3t3& c3t3, const Plane& plane, std::ofstream& out)
+write_surface_cells(const C3t3& c3t3, const Plane& /* plane */, std::ofstream& out)
 {
   for ( C3t3::Cells_in_complex_iterator it_cell = c3t3.cells_in_complex_begin(),
        end = c3t3.cells_in_complex_end() ; it_cell != end ; ++it_cell )