The synthesis of 3-0-acyl derivatives of lupeol is presented, as well as lupenone and the oxime of lupenone. The obtained derivatives were subjected to the MTT test in order to evaluate their cytotoxic activity toward HeLa, KB, MCF-7 and A-549 cell lines in comparison with lupeol (1). The IC₅₀ values for lupeol (1) and all of the tested derivatives (2-6) were from about 7-10 μM for lupenone (5) to about 81 μM for o-phthaloyl-lupeol (4). Acylation of the C-3 hydroxy function of compound 1 decreased the cytotoxic activity of compounds 2-4. The most active anticancer agent was lupenone (5), with IC₅₀ values 7.1-9.1 μM in comparison with 37.7-51.9 μM for lupeol (1).