This study was designed to investigate the effect of pseudo-G-Rh2, a novel metabolite of ginsenoside Rh2, on the apoptosis of SGC-7901 human gastric cancer cells. Pseudo-G-Rh2 demonstrated antitumor activity and significantly inhibited the proliferation of SGC-7901 cells in a concentration-dependent manner. After treatment with pseudo-G-Rh2, SGC-7901 cells showed typical apoptotic morphological features, such as chromatin condensation and DNA fragmentation. Pseudo-G-Rh2 could induce mitochondrial membrane potential loss, which led to the release of cytochrome c (Cyt c), Smac/Diablo and apoptosis-inducing factor (AIF) to the cell cytoplasm. Furthermore, pseudo-G-Rh2 exposure not only decreased the expression of the Bcl-2 protein but also increased the expression of the Bax protein and the activities of caspase-9 and caspase-3 in SGC-7901 cells. These results demonstrated that pseudo-G-Rh2 inhibited the proliferation of SGC-7901 cells by initiating apoptosis. Pseudo-G-Rh2-induced apoptosis was associated with a drop in the mitochondrial transmembrane potential, down-regulation of Bcl-2, up-regulation of Bax and activation of caspase-9 and caspase-3.