The known history of the Old Town of Rethymno, Crete goes back to the Venetian period. From the beginning of the 20th century a number of construction interventions changed the appearance of several buildings of the town. Recently the Municipality of Rethmnon has created a special department for monitoring the numerous development works within the old town. In collaboration with the abovementioned department, the Institute for Mediterranean Studies – F.O.R.T.H. has developed a relational database and a Geographical Information System for the documentation, protection and preservation of the buildings of the Old Town of Rethymno. The final product can be used by the Municipality of Rethymno, the local Department of Antiquities and individual researchers and it can be considered as a pilot system for the management of the cultural resources of the historical centers within an urban environment.