OBJECTIVES: Ulcerative colitis (UC) is an inflammatory bowel disease (IBD) that results from chronic inflammation restricted to all or part of the colon and begins in the rectum. UC significantly impact quality of life and accounts for substantial costs to the health care system and society. The objective of this study was to describe and estimate health care resource utilization in the treatment of UC from a health care system perspective. METHODS: A retrospective study of the Quebec provincial drug reimbursement program (RAMQ) was conducted using a randomly selected group of patients who received at least one diagnosis of UC (ICD-9=556.x) between January 1st, 2010 and December 31st, 2011, but who did not received a diagnosis of Crohn’s disease (ICD-9=555.x). A control group of patients without any diagnosis of UC was created on a 1:1 ratio and matched for age and gender. The difference between the costs of resources consumed during the 2year study period by the two groups (using t-test) provided an estimate of the incremental cost associated with the management of UC.  RESULTS: A total of 2,975 patients with UC were included in the study (mean age =55.5 years, 52% females). During the 2-year study period, patients had received a total of 57,264 scripts for anti-inflammatory drugs, immunosuppressors and/or anti-TNFα agents. The total cost of medical procedures, medications and hospitalizations were higher for UC patients, with an annual incremental cost per patient of CAN$370(95%CI: 331-410), CAN$2,374(95%CI: 2135-2613) and CAN$2,795(95%CI: 2399-3192), respectively. The annual difference in direct costs between UC patients and controls was estimated at CAN$5,539 (95%CI: 5,036-6,043) per patient.  CONCLUSIONS: The present analysis illustrates the high cost of treatments, the high frequency of hospitalizations resulting in increased hospitalization costs and the substantial economic burden, in terms of direct medical costs associated with UC.