AIM: To know the epidemiology and outcome of Crohn′s disease at King Khalid University Hospital, Riyadh, Saudi Arabia and to compare the results from other world institutions.METHODS: A retrospective analysis of patients seen for 20 years (between 1983 and 2002). Individual case records were reviewed with regard to history, clinical, findings from colonoscopy, biopsies, small bowel enema, computerized tomography scan, treatment and outcome.RESULTS: Seventy-seven patients with Crohn′s disease were revisited, 13% presented the disease in the first 10 years and 87% over Ge last 10 years. Thirty-three patients (42.9%)were males and 44 (57.1%) were females. Age ranged from 11-70 years (mean of 25.3±11.3 years). Ninety-two (92%) were Saudi. The mean duration of symptoms was 26±34.7 mo. The mean annual incidence of the disease over the first 10 years was 0.32:100 000 and 1.66:100 000over the last 10 years with a total mean annual incidence of 0.94:100 000 over the last 20 years. The chief clinical features included abdominal pain, diarrhea, weight loss,anorexia, rectal bleeding and palpable mass. Colonoscopic findings were abnormal in 58 patients (76%) showing mostly ulcerations and inflammation of the colon. Eighty nine percent of patients showed nonspecific inflammation with chronic inflammatory cells and half of these patients revealed the presence of granulomas and granulations on bowel biopsies. Similarly, 69 (89%) of small bowel enema results revealed ulcerations (49%), narrowing of the bowel lumen (42%), mucosal thickening (35%) and cobblestone appearance (35%). CT scan showed abnormality in 68(88%) of patients with features of thickened loops (66%)and lymphadenopathy (37%). Seventy-eight percent of patients had small and large bowel disease, 16% had small bowel involvement and only 6% had colitis alone. Of the total 55 (71%) patients treated with steroids at some point in their disease history, a satisfactory response to therapy was seen in 28 patients (51%) while 27 (49%) showed recurrences of the condition with mild to moderate symptoms of abdominal pain and diarrhea most of which were due to poor compliance to medication. Seven patients (33%) remained with active Crohn′s disease. Nine (12%)patients underwent surgery with resections of some parts of bowel, 2 (2.5%) had steroid side effects, 6 (8%) with perianal Crohn′s disease and five (6.5%) with fistulae.CONCLUSION: The epidemiological characteristics of Crohn′s disease among Saudi patients are comparable to those reported from other parts of the world. However the incidence of Crohn′s disease in our hospital increased over the last 10 years. The anatomic distribution of the disease is different from other world institutions with less isolated colonic affection.