We synthesized a number of derivatives of 1,2,3-benzotriazole, 1,2,4-triazole, and oxazolidine-2-one derivatives, among which compounds suppressing the growth of the tumor cells HeLa and H1299 were revealed. The studies of the effect of these compounds on the cell cycle and activity of caspase dependent degradation of poly(ADP-ribose) polymerase showed that these compounds at the IC50 doses exhibit cytostatic effect on tumor cells. In the MCF7 cells, these compounds induce an increase in expression of the tumor suppressor p53.