The aim of the present study was to evaluate the anti-ulcerative colitis activity of Calotropis procera. Different extracts of the investigated plant were evaluated; total alcohol extract, polar extract and non-polar extract. All the investigated extracts at doses 200 &400 mg/kg possessed a dose-dependent anti-ulcerative colitis potential when administrated for 5 consecutive days after colitis induction by acetic acid in rats. They reduced different parameters of UC. Only polar extract at both doses (200, 400 mg/kg) was more effective than the standard drug Prednisolone (50 mg/kg), it produced percent protection of control colitis by 63.8% and78.4% respectively, while the standard drug Prednisolone produced 54.9% protection. The anti-ulcerative colitis activity may be attributed to the active principles i.e. flavonoids. Preliminary phytochemical screening showed that the plant contains flavonoids, unsaturated sterols and/or triterpenoides, cardiac glycosides, carbohydrates or glycosides, proteins and/or amino acids, tannins and coumarins. The total alcohol extract was safe up to 4000 mg/kg and there were no side effects reported on liver and kidney functions. Keywords: Calotropis procera, Anti-ulcerative colitis, Anti-inflammatory, Liver function, Kidney function, Phytochemical screening