BACKGROUND Several guidelines recommend influenza vaccination for high-risk patients, including those on immune-suppressing medications (IS).OBJECTIVE: To assess the vaccination status and immunization history of an outpatient inflammatory bowel disease (IBD) population for H1N1 and seasonal influenza.RESULTS: Among 250 patients, 104 (41.6%) had been immunized against H1N1 and 62 (24.8%) against seasonal influenza, and 158 (63.2%) were taking IS (azathioprine, 6-mercaptopurine, infliximab, adalimumab, methotrexate, cyclosporine or prednisone). Among subjects on IS, the presence of comorbidities warranting vaccination was associated with higher likelihood of H1N1 immunization (62.5% versus 35.8%; P=0.022) but not of seasonal influenza vaccination (25.0% versus 17.2%; P=0.392). Among patients without comorbidities warranting vaccination, IS was associated with a decreased likelihood of vaccination against seasonal influenza (17.2% versus 30.7%; P=0.036) but not H1N1 (35.8% versus 41.3%; P=0.46). The frequency of H1N1 vaccination was significantly higher among patients who visited a general practitioner at least once yearly (45.7% versus 20%; P=0.0027), with a similar trend for seasonal influenza vaccination (27.1% versus 12.5%; P=0.073). Among 91 patients on IS who declined vaccination, 39.6% reported fear of immediate side effects, 29.7% reported concerns about developing serious medical complications, 15.4% reported concerns about activating IBD and 15.4% were not aware that vaccination was indicated.CONCLUSIONS: Current strategies for vaccinating IBD patients on IS are inadequate. Primary care provider education, incentive programs and regular primary care contact may improve immunization uptake.