Numerous studies have focused on the growth regulation effect of vanadium compounds. In our preliminary investigation we have observed growth inhibition of rat hepatoma cell line H35-19 by inorganic vanadium salts. The aim of the present study was to determine the effect of vanadyl sulphate (VOSO4) on autocrine growth and survival of tumorogenic lung (A549) and prostate (DU145) human cell lines. Additionally, non-carcinogenic human cell lines BEAS-2B (as a lung control) and PNT-2 (as a prostate control) were investigated. MTT, modified crystal violet staining, differential staining (HOECHST33258 and PI) methods and assay for anchorage-independent colony formation were used to investigate the effect of vanadyl sulphate. The results showed that VOSO4 significantly inhibited autocrine growth, decreased carcinoma cells viability and increased the ratio of apoptotic and necrotic cells compared to the controls. However, it should be noted that the examined "drug" significantly decreased viability of non-carcinogenic human cell lines (BEAS-2B, PNT-2).