Objectives: This study Investigates the anti-ulcer and anti-inflammatory activity of Cassia fistula (L) stem bark extract in albino wistar rats. Methods: Rats with pylorus ligation and ethanol were used to test for ulcers, while rats with carrageenan-induced paw edema were used to test for anti-inflammatory activity against acute and chronic phases of inflammation. A dose of Cassia fistula (L) (200 and 400 mg/kg p.o.) was given to rats that had been given ethanol and had their pyloruses tied. Rats that had developed pylorus ligation-induced ulcers had their gastric volume, pH, free acidity, and total acidity measured. After receiving treatment with Cassia fistula, ulcers caused by ethanol and pylorus ligation were less common. Results: The antisecretory and cytoprotective properties of the extract may be the causes of the antiulcer activity. Additionally, it demonstrated a highly significant (P 0.001) decrease in inflammation caused by carrageenan induced edema. Conclusion:This study indicates that Cassia fistula (L) bark has anti-inflammatory properties and helps prevent ulcers.