${alpha}$-Curcumene is one of the physiologically active components of Curcuma zedoaria, which is believed to perform anti-tumor activities, the mechanisms of which are poorly understood. In the present study, we investigated the mechanism of the apoptotic effect of ${alpha}$-curcumene on the growth of human overian cancer, SiHa cells. Upon treatment with ${alpha}$-curcumene, cell viability of SiHa cells was inhibited > 73% for 48 h incubation. ${alpha}$-Curcumene treatment showed a characteristic nucleosomal DNA fragmentation pattern and the percentage of sub-diploid cells was increased in a concentration-dependent manner, hallmark features of apoptosis. Mitochondrial cytochrome c activation and an in vitro caspase-3 activity assay demonstrated that the activation of caspases accompanies the apoptotic effect of ${alpha}$-curcumene, which mediates cell death. These results suggest that the apoptotic effect of ${alpha}$-curcumene on SiHa cells may converge caspase-3 activation through the release of mitochondrial cytochrome c.