Starting from (22E)-3alpha,5alpha-cyclo-6beta-methoxystigmast-22-ene eighteen derivatives of (22S,23S)-22,23-oxidostigmastane, (22R,23R)-22,23-oxidostigmastane, and (22R,23R)-22,23-dihydroxystigmastane were synthesized and screened for cytotoxicity in human hepatoma Hep G2 cells and human breast carcinoma MCF-7 cells using MTT assay. Four compounds of this series exhibited high cytotoxicity in both cells; three compounds were selectively toxic in MCF-7 cells, one compound was toxic in Hep G2 cells, rather than in MCF-7 cells; four compounds at low concentrations increased MTT test values over the control.