The aim of this study was to identify disease-related knowledge and information needs of patients with inflammatory bowel disease. The 313 patients (Crohn disease: n = 169, colitis: n = 144) presenting to an outpatient gastroenterology clinic of a tertiary care hospital in Seoul, Republic of Korea, were scored on their knowledge of Crohn disease and colitis and their information needs were assessed in the questionnaire. Patients with Crohn disease obtained a higher mean knowledge score than patients with colitis. The patients with Crohn disease had significantly higher scores about complications than patients with colitis. The patients with Crohn disease showed significantly higher mean scores relating to the patients' information needs than patients with colitis. The favorite topics of information needed were disease, medication, and diagnosis/operations. The patients with Crohn disease wanted more information than patients with colitis about medications used for treatment, daily life, and pregnancy. The effectiveness of the training and education given to patients can be maximized in this education system when the information about disease and medications for Crohn disease patients or information about disease and diet for colitis patients is primarily provided according to the degree of the patients' need for information.