Background Numerous studies from Europe and North America have provided a wealth of information regarding the epidemiological and clinical characteristics of inflammatory bowel disease (IBD) in Caucasians. Previous studies in mainland China have been limited by small patient numbers or by lack of detailed information about clinical subgroups of the disease. This study was carried out to assess the demographic and clinical characteristics of IBD in Chinese patients. Methods In the Sir Run Run Shaw Hospital between 1994 and 2003, 379 patients were diagnosed as IBD. Demographic and clinical data were collected and analysed. Results Of 379 patients, 317 had ulcerative colitis (UC) (83.6%, 168 male, 149 female, male-female ratio 1.13∶1, age range at diagnosis 14-79 years, mean age 44 years) and 62 had Crohn’s disease (CD) (16.4%, 39 male and 23 female, male-female ratio 1.70∶1, age range at diagnosis 13-70 years, mean age 33 years). In UC, 11.4% of patients had proctitis, 25.2% had proctosigmoiditis, 18.6% were diseased to the splenic flexure and 44.8% had extensive colitis. Nine patients with UC (2.8%) had arthritis, three patients (0.9%) had iritis or conjunctivitis. Of the 62 CD patients, 16 (25.8%) had diseases restricted to the terminal ileum; 15 (24.2%) had colonic diseases; 20 (32.3%) had ileocolonic disease and 11 (17.7%) had disease involving the upper gastrointestinal tract. Conclusions This study shows similar caracteristics of IBD to that in the West but there are some differences with respect to severity and extraintestinal manifestations. The ethnic and geographic differences may give important clues to the aetiology of IBD. Background Numerous studies from Europe and North America have provided a wealth of information regarding the epidemiological and clinical characteristics of inflammatory bowel disease (IBD) in Caucasians. Previous studies in mainland China have been limited by small patient numbers or by lack of detailed information about clinical This study was carried out to assess the demographic and clinical characteristics of IBD in Chinese patients. Methods In the Sir Run Run Shaw Hospital between 1994 and 2003, 379 patients were diagnosed as IBD. Demographic and clinical data were collected and Results Of 379 patients, 317 had ulcerative colitis (UC) (83.6%, 168 male, 149 female, male-female ratio 1.13:1, age range at diagnosis 14-79 years, mean age 44 years) and 62 had Crohn’s disease (CD) (16.4%, 39 male and 23 female, male-female ratio 1.70:1, age range at diagnosis 13-70 years, mean age 33 years) In UC, 11.4% of patients had proctitis, 25.2 % Had proctosigmoiditis, 18.6% were diseased to the splenic flexure and 44.8% had extensive colitis. Nine patients with UC (2.8%) had arthritis, three patients (0.9%) had iritis or conjunctivitis. Of the 62 CD patients, 16 (25.8 had (32.3%) had ileocolonic disease and 11 (17.7%) had disease involving the upper gastrointestinal tract. Conclusions This study shows similar caracteristics of IBD to that in the West but there are some differences with respect to severity and extraintestinal manifestations. The ethnic and geographic differences may give important clues to the aetiology of IBD.