Objective: Ulcerative colitis has a world-wide distribution but its prevalence and clinical patterns in Pakistan are not known. This study was performed to ascertain the clinical patterns of ulcerative colitis in patients referred to a tertiary care center. Methods: All patients presenting with diarrhea, blood in stools and biopsy proven for ulcerative colitis were prospectively followed for clinical features, laboratory findings, endoscopic features and treatment response over the study period. Results: A total of 85 patients were seen and followed for up to 8 years. All had diarrhea with blood in stools. All had numerous white blood cells in stool. Erythrocyte sedimentation rate was elevated in 94 % of patients. More than half had mild disease and distal colitis. All patients responded well to standard treatment with anti-inflammatory drugs. Conclusion: Most patients of ulcerative colitis were mild in severity and had distal involvement. Clinical features in this cohort were similar to patients in most other parts of world. All responded to standard treatment.