Background: Ulcerative Colitis (UC) is a chronic condition that represents a group of intestinal disorders causing prolonged inflammation of the digestive tract. Nowadays, efforts to investigate new remedies have led to a committed movement toward the integration of traditional and complementary medicine into mainstream medicine. In Traditional Persian Medicine (TPM), Maqliasa is one of the most frequent gastrointestinal prescriptions which is claimed to be effective in both remission and recurrent phases of UC. Objective: The aim of this pilot study was to examine the effect of Maqliasa on UC symptoms. Methods: Through a non-randomized before-after uncontrolled clinical trial, 13 outpatients with active UC were enrolled in the study. They continued their conventional drug regimens plus Maqliasa capsules (2 capsules t.i.d.) for 28 days. Three visits were arranged for each patient− the first admission, day 14th admission and day 28th admission. The patients were evaluated by Lichtiger Colitis Activity Index. Wilcoxon signed-rank test was used for statistical analysis. Results: The Lichtiger colitis activity index improved in the study group was compared to the corresponding baseline values: baseline score: 7.8 ± 0.5; after two weeks: 5.9 ± 0.6 (P=0.002); after four weeks: 3.6 ± 0.5 (P=0.001). Conclusion: This study showed the promising effect of Maqliasa in the treatment of active UC. However, due to some of the limitations of the study, conducting future high-quality randomized clinical trials would be crucial.