In the context or Eastern Mediterranean geology, the three ophiolitic massifs of Troodos (Cyprus), Hatay (Turkey) and Baër-Bassit (Syria) can be considered, in many ways, as a coherent ensemble. Lapierre et al. (1972) have shown that the Paphos region of Cyprus and Baër-Bassit are similar, while Parrot (1976) has described the close relationship between Baër-Bassit and the Hatay. Many similarities are also evident in the geochronological data. The gabbros, in particular, have given similar·Cretaceous rediometric ages. On the other hand, dates from the Hatay pillow-lavas lncidate that they have been affected by more recent events than those of Troodos. Good radiometric ages, in aggrement with paleomagnetic and stratigraphic data, are essential to the correct paleogeographic reconstructions of the region concerned. However, the problem in dating ophiolitic rocks is that the majority have been transformed mineralogically and chemically, either on the ocean floor or during emplacement to their present positions. The interpretation of the dates measured, is therefore, difficult. The scatter of dates obtained in our study can be explained by variable radiogenic argon loss or perhaps, by addition of potassium probably from sea-water (halmyrolysis). The presence of excess argon need not be invoked to explain these variations.