Objective: The anticarcinogenic activity of saffron was showed in several studies. In the present study, safranal was choosed as component of saffron to clear the role of this compound in the cytotoxic effect of saffron. Safranal is a monoterpene aldehyde which is the major constituent of the essential oil of saffron. Cytotoxic effect of safranal, and its nanoliposomal form to improve safranal cellular delivery were investigated in this study. Materials and Methods: To prepare multilamellar liposomes (MLVs) of Safranal, Solvent Evaporation method was used.Cell viability was quantitated by MTT test. PI staining of DNA fragmentation by flow cytometry (sub-G1 peak) was used to determination of apoptotic cells. Results: The results showed that safranal and its nanoliposomal form decreased cell viability in a time and dose dependent manner. Safranal Liposomal form (in IC50 conc.) showed enhanced effect compared to the safranal solution. Safranal increased sub-G1 population (as a marker of apoptosis ) in flow cytometry histogram of treated cells compared to control. Conclusion: In this study, safranal, one of the main ingredients of saffron, showed cytotoxic effect on Hela and MCF 7 cancer cell lines. Liposomal safranal had better toxicity effect than safranal. Flow cytometry results showed apoptotic cell death is involved in safranal toxicity in cancer cell line. Safranal could be involved in saffron anti-tumor properties. Liposome encapsulation could also increase cytotoxic effects of saffranal.