Helicobacter pylori deregulates the genes that control homeostasis between apoptosis and cell proliferation of gastric epithelial cells. Nuclear factor-κB (NF-κB) has an important role in H. pylori-induced apoptosis in gastric epithelial cells. The peroxisome proliferator-activated receptor-γ ligand 15-deoxy-Δ12,14-prostaglandin J 2 (15d-PGJ2) regulates growth and the signaling cascade in H. pylori-infected gastric epithelial cells. In the present study, we determined whether 15d-PGJ2 inhibits apoptosis by regulating apoptotic gene expression and NF-κB activation in gastric epithelial cells infected with CagA+, VacA+ H. pylori in a Korean isolate (HP99). 15d-PGJ 2 was found to inhibit H. pylori-induced DNA fragmentation and cell death. 15d-PGJ2 induced downregulation of proapoptotic Bax and upregulation of antiapoptotic Bcl-2 as well as suppression of NF-κB activation caused by H. pylori in gastric epithelial cells. The results suggest that 15d-PGJ2 inhibits apoptotic cell death by inhibiting NF-κB activation and apoptotic gene expression in gastric epithelial cells.