Spondias mombin L. (Anacardiaceae) commonly known as ̒yellow mombin̕ is a multipurpose herb cultivated in parts of the Brazilian Northeast for its edible fruits, oil and leaves. The bark is used to carve figures and the leaves and roots used as medicine. The objective of this study was to evaluate the effect of aqueous leaf extract of Spondias mombin Linn. on gastric ulcers. The effect was evaluated in ibuprofen, alcohol and pylorus ligation-induced gastric ulcer models. The extract was administered orally at three different doses of 50, 100 and 200 mg/kg. The antiulcer activity was accessed in rats by comparing the ulcer index in the test group with that of the control (distilled water) and standard (omeprazole, misoprostol) groups. The involvements of endogenous nitric oxide, prostaglandins and non-protein sulfhydryl groups in the cytoprotective action of Spondias mombin L. were also investigated. The extract showed a significant (p<0.05, p<0.01, p< 0.001) antisecretory and gastric cytoprotective effects in pylorus ligation, alcohol and ibuprofen-induced ulcer model respectively. Antioxidant analysis showed significant scavenging of free radical using nitric oxide, reducing power activity and DPPH assay. Spondias mombin L. showed presence of flavonoids, tannins, reducing sugar, cardiac glycosides and terpenes. The experiment suggests a possible participation of NO synthase and NP-SH pathways in the gastroprotective effect of Spondias mombin.