Potassium-Argon ages were determined on ophiolitic rocks of central and eastern Crete. Two major group of ages - Lower to Mid Cretaceous and Eocene - were found. Cretaceous ages occur in central Crete and Eocene ages are more common in Eastern Crete and totally absent in central Crete. Cretaceous ages agree fairly well with the general outline. On the contrary Eocene ages can be explained neither by a rejuvenation process nor by a differentiation process taking place later on.