An enriched population of isolated gastric parietal cells was obtained from canine gastric mucosa. Parietal cells incubated with [14C]arachidonic acid produced radiolabelled PGF2 alpha, PGE2, PGD2 and 6-keto PGF1 alpha (acid hydrolysis product of PGI2). The prostaglandin synthesis was inhibited by indomethacin. Prostaglandin production, as measured by gas chromatography-mass spectrometry demonstrated that PGF2 alpha was produced in the highest quantity followed by PGE2 and 6-keto PGF 1 alpha. This demonstrates that isolated prietal cells are capable of producing prostaglandins. Since prostaglandins have a potent effect on gastric acid secretion, local prostaglandin synthesis could modulate parietal cell function.