Objectives: The aim of the research was to examine the potential cytotoxicity of newly synthesized thienopyridine derivatives on HeLa and SiHa human cervical cancer cells. The assumption is that the metabolic activity of the cells will decrease after exposure to the derivative compared to the control group. Materials and methods: Cytotoxicity was tested by the MTT method, which determines the percentage of metabolically active cells after treatment with thienopyridine derivatives (inhibitors 5, 6, 8 and 9). The derivatives were prepared in 7 different concentrations: 0.05, 0.2, 0.5, 1, 2.5 and 10 μmol/L. The time of exposure of cells to inhibitors was 4, 24, 48 and 72 h. The effectiveness of the derivatives was measured spectrophotometrically at 570 nm. Results: Inhibitors 5, 6, 8 and 9 showed significant cytotoxic activity on both HeLa and SiHa cell lines. Cytotoxicity depends on the concentration and time of exposure of the cells. The most effective inhibitor for the HeLa cell line is inhibitor 5. Inhibitor 8 showed the greatest impact on the metabolic activity of the SiHa cell line. Conclusions: Cytotoxicity testing of newly synthesized pyridine derivatives showed significant activity of all derivatives on both cell lines. The results are similar for HeLa and SiHa cells. The activity depends on the concentration and time of exposure of the cells to the derivatives. The hypothesis of this research was confirmed, and the objectivities achieved. Further in vitro tests and confirmation of the results as well as in vivo animal studies are required.