In vitro study and characterization of anticancer activity of new heterocyclic derivati ve -N(5methyl [1,3,4]thiadiazol2yl)propionamide. Methods. The cell culture; MTT assay. Results. We synthesized N(5methyl[1,3,4]thiadiazol2yl)propionamide, which possessed diuretic, cardioprotective, and anti-inflammatory effects. Here, we investigated its cytotoxi ci ty effect towards the tumor cell lines of various tissue origins: liver (HepG2), breast (MCF7), lung (A549), cervical (KB31), and leukemia (HL60) cells, as well as towards the non-tumor cells (НЕК293 and NIH3T3). The IC 50 values of the synthesized compound for tumor cells were in the range of 9.4-97.6 μg/mL. We found that the human hepatocellular carcinoma HepG2 cells were the most sensitive to the action of N(5methyl[1,3,4]thiadiazol 2yl)propionamide with the IC 50 value of 9.4 μg/mL. The studied derivative slightly inhibited the growth of the pseudonormal HEK293 and NIH3T3 cells. Conclusions. The antipro li fe rative activity of N(5methyl[1,3,4]thiadiazol2yl)propionamide dropped in the order: hepatocarcinoma > leukemia > breast carcinoma cells. Thus, we revealed in the molecule of N(5methyl[1,3,4]thiadiazol2yl)propionamide a combination of the diuretic, cardioprotec tive, anti-inflammatory and anticancer activities, which is of great significance for this agent as a potent anticancer medicine. K e y w o r d s: N(5methyl[1,3,4]thiadiazol2yl)propionamide, cytotoxicity in vitro, anti cancer activity.