The mechanisms of apoptosis induced by diallyl disulfide (DADS) were explored in human cervical cancer Ca Ski cells. Flow cytometric analysis, DNA gel electrophoresis and DAPI staining demonstrated that DADS induced apoptosis in Ca Ski cells. DADS induced apoptosis through the production of reactive oxygen species and Ca2+, and induced abrogation of mitochondrial membrane potential (Deltapsim) and cleavage of Bid protein (t-Bid). DADS increased the levels of p53, p21 and Bax, but caused a decrease in the level of Bcl-2. DADS also promoted the activities of caspase-3 leading to DNA fragmentation, thus indicating that DADS-induced apoptosis is caspase-3 dependent. In addition, DADS induced an increase in the level of cytochrome c in the cytoplasm, which was released from mitochondria. BAPTA attenuated the Deltapsim abrogation and significantly diminished the occurrence of DADS-induced apoptosis in Ca Ski cells. In conclusion, DADS-induced apoptosis occurs via production of ROS and caspase-3 and a mitochondria-dependent pathway in Ca Ski cells.