Introduction: Malignant diseases are worlds second leading cause of death. The request for anti-tumor drugs is growing due to a large number of deaths caused by malignant changes. One of the most used chemotherapeutics is cisplatin. However, cisplatin use led to numerous side effects. Because of this, our attention is shifted to palladium, which forms complexes same as platinum, so may be a supstitute for platinum. Objective: To research the cytotoxic effect of palladium (II) complexes on the growth of four cell lines (PANC1, BJ, MDCK.1, NCI-H358) under in vitro conditions. Materials and methods: Palladium (II) complexes were synthesized at the Faculty of Food Technology in Osijek, Subdepartment of Chemistry and Ecology, at the Department of Applied Chemistry and Ecology. Compounds were made by dissolvment of 100% DMSO in concentration of 10-2 mol/dm3 (M), and final count of concentrations was 10-4 M, 10-5 M and 10-6 M. Cultivation of the cells was carried out in an CO2 incubator at 37°C. The cell viability was determined by MTT assay after 72-hour incubation. Results: An antiproliferative effect of the tested compounds on cell lines was observed. A higher cytotoxicity was noticed at higher concentrations of the tested chemical compounds. Most effective antiproliferative action were showed by Pd 1 and Pd 4, on all tumor cells at concentration of 10-4 M. Normal cells that originated from humans, BJ, showed a good resistance for tested samples and with survival percentage of about 50-65% within highest concentration. Largest sensitivity showed mouse MDCK1 colony. Conclusion: Palladium (II) complexes reduce the growth of tumor cells. The inhibition of growth depends on the concentration of the compound and the cell line type.