The synthesis and anticancer activity of novel 2-amino-4-(4-phenylpiperazino)-1,3,5-triazine derivatives 4a-b and 5a-f are described. Compounds 4a, 5a,c and 5f were evaluated by in vitro assays of growth inhibition against several human tumor cell lines. The vitro cytotoxic activity was found for 2-{2-amino-4-[4-(2-chlorophenyl)piperazino]- 1,3,5-triazin-6-yl}-3-(4-nitrophenyl)acrylonitrile (5f) (IC50 = 0.45 microM - 1.66 microM), whilst other tested compounds were inactive. Some of the molecular orbital calculations for the tested derivatives were also presented.