A multiple choice knowledge questionnaire was developed for patients with inflammatory bowel disease (IBD). Initially, 20 questionnaires were piloted, and then questions of poor discriminatory ability (> 75% patients giving a correct response) were eliminated. A second pilot study proved the internal consistency (coefficient alpha = 0.84) and the stability of the questionnaire using a test-retest method (Spearman R = 0.86, p = 0.002). The questionnaire was then completed by 60 randomly selected patients attending colitis clinic. The mean score was 13 of a total of 36 (range 2-29). Eighty percent of patients wished to know more about their disease. Knowledge score was higher in patients who were members of the National Association of Crohn's Disease and Colitis (NACC) (p < 0.005) and in patients with Crohn's disease (CD) rather than ulcerative colitis (UC) (p < 0.005). Knowledge score correlated with the number of years spent in full-time education (R = 0.48, p < 0.001) and inversely with age (R = -0.33, p < 0.02) but did not correlate with disease duration. The study demonstrated some misunderstandings about IBD although most patients would have liked more information. The questionnaire could be used as a tool to evaluate patient education programs.