Melastoma malabathricum L. Smith (Melastomaceae) has been used in the Malay traditional culture to treat ulcer-based ailments.The objective of the present study was to investigate the potential anti-ulcer effect of aqueous extract of M. malabathricum leaves (AEMM) using ethanol- and indomethacin-induced gastric ulcer models in rats. Rats were divided into ten groups (n=6) and received DMSO (10%; negative group), ranitidine (100mg/kg; positive group) or AEMM (50, 250 and 500mg/kg) orally for 7 days and on the 8(th) day subjected to the respective gastric ulcer models. The stomachs were collected and subjected to macroscopic and microscopic analysis. At all groups tested, the AEMM exerted significant (p<0.05) anti-ulcer effect only against the ethanol-induced gastric ulcer model. The percentage of anti-ulcer for the 50-500mg/kg AEMM ranging between 50-82%, respectively. The macroscopic observations were supported by histological findings. In conclusion, AEMM exhibits potential anti-ulcer activity attributed to its previously proven high flavonoids content and antioxidant activity.