Moringa oleifera Lam. (Moringaceae) is widely consumed in tropical and subtropical regions for their valuablenutritional and medicinal characteristics. Recently, extensive research has been conducted on leaf extracts of M.oleifera to evaluate their potential cytotoxic effects. However, with the exception of antimicrobial and antioxidantactivities, little information is present on the cytotoxic activity of the essential oil obtained from M. oleifera seeds.Therefore, the present investigation was designed to investigate the potential cytotoxic activity of seed essentialoil obtained from M. oleifera on HeLa, HepG2, MCF-7, CACO-2 and L929 cell lines. The different cell lineswere subjected to increasing oil concentrations ranging from 0.15 to 1 mg/mL for 24h, and the cytotoxicity wasassessed using MTT assay. All treated cell lines showed a significant reduction in cell viability in response to theincreasing oil concentration. Moreover, the reduction depended on the cell line as well as the oil concentrationapplied. Additionally, HeLa cells were the most affected cells followed by HepG2, MCF-7, L929 and CACO-2,where the percentages of cell toxicity recorded were 76.1, 65.1, 59.5, 57.0 and 49.7%, respectively. Furthermore,the IC50 values obtained for MCF-7, HeLa and HepG2 cells were 226.1, 422.8 and 751.9 μg/mL, respectively.Conclusively, the present investigation provides preliminary results which suggest that seed essential oil fromM. oleifera has potent cytotoxic activities against cancer cell lines.