Apoptotic cell death is a highly regulated process, which plays a crucial role in many biological events. The aim of the present research was to investigate the expression of the apoptosis related genes BCL2 and BAX in Hep-2 and HL60 cells. Apoptosis was induced in these cell lines during treatment with etoposide. The expression levels of BCL2 and BAX genes were measured after 6 h and 12 h of treatment by quantitative real-time RT-PCR. In Hep-2 cells the expression level of BCL2 significantly increased both 6 h and 12 h of treatment, whereas expression level of BAX didn't change. In HL-60 cells the expression level of BCL2 decreased after 6 h of treatment and expression of BAX increased both 6 h and 12 h of treatment with etoposide. Those findings show distinct reactions of Hep-2 and HL-60 cells to etoposide treatment and different upregulation or downregulation of apoptosis-related genes BCL2 and BAX.