In this study, the cytotoxic effects of aqueous and ethanolic extracts of Sedum album L. on human stomach cancer cell line (AGS) and breast cancer cell line (MCF-7) were evaluated by MTT, BrdU and TUNEL assays. The results demonstrated that both extracts had antiproliferative and apoptotic effects in a dose-dependent manner. The MTT assay data revealed that the AGS cell underwent more cytotoxicity in comparison with the MCF-7 cell. It also revealed that ethanolic extract was more potent than aqueous extract. The BrdU assay results showed that the proliferation of AGS and MCF-7 cells was reduced to 50% and 43%, respectively, at the highest concentration of the aqueous extract. In addition, the ethanolic extract reduced the proliferation of AGS and MCF-7 cells to 75% and 60%, respectively. The AGS and MCF-7 cells underwent 52% and 12% apoptotic death upon treatment by the ethanolic extract as TUNEL assay showed. The aqueous extract induced 28% and 25% apoptosis in the AGS and MCF-7 cells, respectively. Both inhibition of proliferation and induction of apoptosis are desirable strategies for cancer treatment among researchers. Identification of S. album compounds and analyzing their effects in animal model of cancer can help us with understanding its anti-cancer properties.