Background: Ulcerative colitis is incurable, relapsing, and remitting intestinal disease that often requires lifelong treatment usage to maintain remission. Compliance is defined as the practice of obeying rules or requests made by people in authority. Aim of the study: this study aimed to assess patients' compliance to Therapeutic regimen among patients with ulcerative colitis. Research Design: Descriptive exploratory design was utilized to conduct this study. Settings: The study was conducted at gastroenterology outpatient clinic affiliated to Ain Shams University Hospitals. Study subjects: A purposive sample of 93 patients with ulcerative colitis was recruited in this study.Tools:1) patient interviewing questionnaire. 2) Patients' knowledge regarding ulcerative colitis questionnaire. 3) Compliance assessment tool. Results: the patient had 71% unsatisfactory knowledge about ulcerative colitis.79.6% of them had noncompliance regarding ulcerative colitis therapeutic regimen.59.2% of the studied patient had insufficiently active physical activity. Conclusion: Less than three quarters of the studied patients had unsatisfactory knowledge about ulcerative colitis. Also, more than three-quarters of the studied patients were non-compliant with the ulcerative colitis therapeutic regimen, More ever less than two third of the studied patients were insufficiently active regarding physical activity. Recommendations: Patients and their families should be provided with adequate knowledge about ulcerative colitis and the importance of proper compliance to therapeutic regimen, replication of the current study on a larger sample to achieve generalization of the results.