Background & Aims: This study was conducted to assess, in a small sample, the short-term outcomes of once-daily mesalamine versus conventional dosing in maintaining quiescent ulcerative colitis (UC) and to assess adherence rates with both regimens. Methods: Consecutive patients were randomly assigned to either a once-daily regimen, or they continued current conventional regimen (twice daily or 3 times daily). Patients were assessed at 3 months and 6 months. At each point, a clinical symptom disease score was obtained using patient questionnaires, and medication rates via pharmacy data. Adherence was defined as consumption of >80% of prescribed medication. Information was collected by an investigator blinded to treatment regimen. Results: Twenty-two patients were enrolled in the study, 12 in the once-daily group (QD) and 10 in the conventional group (CD). At 3 months, no patients had experienced a relapse. All of the patients in the QD group and 70% of patients in the CD group were adherent (P = 0.04). The average amount of medication consumed in the QD group was significantly higher than in the CD group (90% vs. 75%, P = 0.02). At 6 months, 2 patients (1 patient from each group) experienced a clinical relapse (P = 0.76). Seventy-five percent vs. 70% of patients were adherent (P = 0.8); the amount of medication taken approached significance (90% vs. 76%, P = 0.07). All patients in the QD group reported being either "very satisfied" or "satisfied" with their regimen. Conclusions: In this randomized pilot trial, patients taking once-daily mesalamine had outcomes similar to those for patients on conventional regimens. A larger trial is warranted to assess whether true differences between regimens exist.