The Cu(II) complexes with N(4)-((4)-ethyl benzoate) thiosemicarbazone of 2-formylpyridine: [Cu(L)Cl] (1), and [Cu(L)Br] (2) (Fig.1.) were synthesized as described in the literature [1]. The complexes (1, 2) were characterized by FT-IR spectroscopy, molar conductivity, magnetic susceptibility measurements, elemental analysis and melting points. The physicochemical and spectral characteristics correspond to the literature data [1].formulaFig. 1. Structural formula of the [Cu(L)Cl] (1) and [Cu(L)Br] (2) Analysis of genomic DNA reveals the ability of compounds to induce apoptosis in cells. It was carried out as per DNA fragmentation analysis on 0,8% agarose gel (100V, 30 min) [2]. Human cervical adenocarcinoma cells (HeLa line) were treated with complexes 1, 2 (5μM) for 24h. The tested complexes 1, 2 have demonstrated the ability toward cleavage of genomic DNA. Thus, the tested compounds showed antiproliferative action associated with dating increased apoptosis induction, breaking genomic DNA structures in the cell nucleus. This fact is very important because cellular death is the underlying pharmacological purpose of chemotherapy. Possibly, the antiproliferative activity of Cu(II) complexes (1, 2) can be caused by the coordination of N(4)-((4)-ethyl benzoate) thiosemicarbazone of 2-formylpyridine (HL) to the copper central atom, which leads to a change of electron density in the thiosemicarbazone moiety. Therefore, a copper atom in this coordination compound can coordinate DNA molecules. The electrophoresis method of DNA defragmentation confirms the mechanism of action of the studied substances linked with a direct effect on genomic DNA cells. The research findings identified a possible mechanism of action of the tested compounds associated with cellular apoptosis.