Abstract Background: Inflammatory bowel disease (IBD), including Crohn's disease (CD) and Ulcerative Colitis (UC), is a chron-ic gastrointestinal condition affecting over 6.8 million people globally. It is linked to relapse and remission, necessitating reg-ular monitoring for disease activity. Aim of Study: To evaluate Faecal Myeloperoxidase (fMPO) as a potential marker of activity in patients confirmed to have UC compared to C-reactive protein (CRP) and faecal Calpro-tectin (fCAL), which are the standard laboratory markers to in-itially diagnose activity in quiescent UC. Patients and Methods: This cross-sectional study was con-ductedon 39 patients, divided into 3 groups with ulcerative co-litis attending The Memorial Souad Kafafi University Hospital, Misr University for Science and Technology. Group 1: Newly diagnosed patients (15 patients). Group 2: Patients on No-bi-ological therapy (11 patients). Group 3: Patients of biological therapy (13 patients). Results: The study demonstrated a significant positive cor-relation between fCAL and Mayo score, but no correlation was found between Mayo score and fMPO. However, a significant positive relation was found between fCAL and disease activity groups, with a difference between mild and moderate disease activity groups. The area under curve for fCAL was excellent in distinguishing between moderate and mild disease groups, with a sensitivity of 85.7% and specificity of 87.5%. Conclusion: The study demonstrated that fMPO is effec-tive in stratifying UC patients' activity, while fCAL showed the best diagnostic ability. Combining markers could improve diagnostics.