The aim of this study was to assess the possible protective effect of sphingosine-1-phosphate (S1P), a polar sphingoid metabolite that seemingly promotes cell survival, on cytotoxin- and irradiation-induced ovarian injury in the rat model. Administration of S I P into ovarian bursa before whole-body irradiation led to decreased percentage of apoptotic cells, mostly in primordial follicles; however, S1P was not effective against apoptosis in rats that were given intraperitoneal cyclophosphamide.