Introduction: Curcumin, a natural compound present in turmeric (Curcuma longa) has been known to possess both anti-inflammatory and antioxidant effects. Objectives: The objectives of the study were to evaluate the cytotoxic activities and to determine the mode of cell death induced by curcumin towards the human mammary carcinoma cells (MDAMB-231). Methodology: Cytotoxicity of curcumin and its effect on cell viability were determined by using MTT assay and trypan blue dye exclusion method, respectively. The mode of cell death was detected by viewing under a light microscope and through DNA fragmentation analysis. Results and discussion: Curcumin was cytotoxic to MDA-MB-231 cells with the IC50 of 17.25 ì g/ml. Cell viability treatment using curcumin at concentrations of 30 ì g/ml and 10 ì g/ml was significantly (p