The conservation of works of art includes their restoration and preservation. Control over environmental conditions in Museums is quite a new science which is not as yet included in the history of conservation. The basic reasons for the deterioration of works of art (in museums and galleries) are three: 1) strong light and UV radiations 2) pollution of the air and 3) humidity. The situation in Greece is not brilliant, for the moment, but we hope to see some improvement as countries reconsider their role in the preservation of historic monuments and of works of art.