We report four new cases of oral manifestation in Crohn's disease (CD) and evaluate 75 reported cases for morphology and site of oral and intestinal manifestations of CD, clinical manifestation, and treatment. Oral CD was the presenting symptom in 43 of 72 (60%) patients and relapsed in 34 of 60 (57%). Median age at presentation was 22 (range 6-57) years, and males were affected more often (1.85:1, male:female ratio). From a total of 228 oral lesions in 79 patients, lips (57 lesions), gingiva (40 lesions), vestibular sulci (31 lesions), and buccal mucosa (25 lesions) were the sites most frequently affected. Edema (62 lesions), ulcers (57 lesions), and polypoid papulous hyperplastic mucosa (45 lesions) were the most common type of lesions. The rate of granuloma detection was high in oral (67-77%) and intestinal lesions (45-71%). A total of 66 courses of drug therapy in 51 patients were analyzed. Complete remission of oral symptoms was achieved by systemic steroids and/or azathioprine in 13 of 26 (50%) patients, whereas strictly topical treatment with steroids resulted in complete remission of oral symptoms in 7 of 12 (58%). We conclude that oral CD exhibits a characteristic morphologic appearance, as often as not preceding intestinal symptoms in adolescents and young adults. Thus, patients with orofacial granulomatosis CD should be vigorously searched for by complete gastrointestinal endoscopic investigation. Oral CD may cause disabling pain and facial distortion, and results of treatment remain unrewarding. In the absence of data from controlled therapeutic trials, systemic steroids and/or azathioprine are recommended if topical treatment has failed to control symptoms.