Introduction: Quinoline is a heterocyclic organic compound consisting of a fused benzene and pyrimidine ring which have a high modification ability. Precisely because of this ability it is possible to synthesize various types of quinoline derivatives which have shown useful anti-tumor properties during the study. Quinoline derivatives are very attractive compounds for research as they have shown a wide spectrum of various biological activities, both antitumor and antibacterial, anticonvulsant, analgesic and anti-inflammatory. Objective: To investigate the cytotoxicity of eight different quinoline arylamidine hybrids in four human cell lines of leukemia and lymphoma (K562, CCRF - CEM, Raji and HuT - 78). Materials and Methods: Quinoline arylamidine derivatives were synthesized at the Institute of Applied Chemistry and Ecology at the Faculty of Food Technology in Osijek, and the cell lines were commercially purchased. The derivatives were dissolved in DMSO as a concentrated 1·10⁻2 M solution prior to use in the study, while the dilutions were prepared immediately prior to application to the cells and applied at concentrations of 1·10 ⁻⁴ M, 1·10⁻⁵ M and 1·10⁻⁶ M. Cell culture was carried out in an incubator at 5% of carbon (IV) dioxide, at a temperature of 37°C and with high humidity. The cytotoxicity of the applied compounds was determined using the MTT test and by reading the absorbance on the spectrophotometer. Results: Concentrations of 1·10⁻⁵ M and of 1·10⁻⁶ M in all cell lines are observed to cause no significant inhibitory effect. Significant inhibitory effect on the investigated cell lines showed all derivatives applied at a concentration of 1·10⁻⁴ M but the effect was the best when using derivatives 2 and 8. Generally, the highest susceptibility to the derivatized derivatives was demonstrated by the HuT-78 cell line. Conclusion: Quinoline arylamidine hybrids reduce the growth of tumor cells of leukemia and lymphoma, but the percentage of inhibition depends on the concentration of the compound and the cell line type.