Purpose: The aim of the present study was to investigate perceived oral health in patients with Crohn's disease (CD) in comparison with a control group without CD. Materials and Methods: The study population comprised 1943 patients with CD recruited from the Swedish National Patients Organisation of inflammatory bowel disease and 1000 randomly selected controls. All participants received a questionnaire with questions concerning socioeconomic variables, education, civil status, income, dental care habits, oral health and tobacco use. Results: Eighty-eight per cent of the patients and 75% of the controls answered the questionnaire. Patients with CD perceived their oral health to be worse than controls. The odds ratio (OR) for the patients to estimate their oral health as much worse than others in the same age group was 9.7 (95% CI, 5.8 to 16.4) after adjustment for age, smoking habit, gender and education. The patients also reported a significantly greater need for dental treatment than the controls, with an OR of 5.7 (95% CI, 4.2 to 7.9) after taking into account the age, smoking habit, gender and education. Furthermore, the patients with CD reported significantly more mouth-related problems than controls (OR 3.2), such as significantly more caries and more gingival bleeding. Of note, there were significantly more smokers in the patient group. Conclusions: The results of the present study show that patients with CD perceived their oral health to be worse and have a greater need for dental treatment compared with the control group. Schlagwörter: Crohn's disease, oral health, questionnaire