Curcumin, a polyphenol compound derived from the rhizome of the plant Curcuma longa L. has been verified as an anticancer compound against several types of cancer. However, understanding of the molecular mechanisms by which it induces apoptosis is limited. In this study, the anticancer efficacy of curcumin was investigated in human gastric adenocarcinoma SGC-7901 cells. The results demonstrated that curcumin induced morphological changes and decreased cell viability. Apoptosis triggered by curcumin was visualized using Annexin V-FITC/7-AAD staining. Curcumin-induced apoptosis of SGC-7901 cells was associated with the dissipation of mitochondrial membrane potential (MMP) and the release of cytochrome c into the cytosol. Furthermore, the down-regulation of Bcl-2 and up-regulation of Bax that led to the cleavage of caspase-3 and increased cleaved PARP was observed in SGC-7901 cells treated with curcumin. Therefore, curcumin-induced apoptosis of SGC-7901 cells might be mediated through the mitochondria pathway, which gives the rationale for in vivo studies on the utilization of curcumin as a potential cancer therapeutic compound.