A revision of the parasitic protozoan genus Sarcocystis which has reptiles as intermediate and/or final hosts is given. Twelve species described as having reptiles as intermediate hosts are considered valid species of the genus Sarcocystis. Snakes have been shown experimentally to be the final hosts of ten other Sarcocystis species which have rodents as their intermediate hosts. One species, S. podarcicolubris, has poikilothermic intermediate and final hosts. Classification of a new Sarcocystis species based either on scantily described cysts or only on sporulated oocysts or sporocysts from feces is not sufficient and cannot be justified. A new species should be recognised only after experimental retransmission and/or because of unequivocal morphological characteristics of the sarcocyst.