Inflammatory bowel disease (IBD) is commonly associated with arthritic manifestations. They are divided into three clinical categories; peripheral arthritis, spondylitis, and sacroiliitis. To evaluate the incidence of arthritis associated with IBD in Korea, we retrospectively reviewed one hundred and twenty-nine patients with IBD, 77 with ulcerative colitis (UC) and 52 with Crohn's disease (CD). Arthritis occurred in twenty-two patients (17.1%); 15 with UC(19.6%), 7 with CD (13.5%). Patients with arthritis had more active inflammations and all were seronegative except one patient. Peripheral arthritis was found in twenty patients (15.5%) and more common in UC (19.6%) than in CD (9.6%). Joint involvements tended to be monoarticular or pauciarticular, and most frequently developed in the knee and ankle. Spondylitis was diagnosed in one patient (1.6%) who showed HLA B27 positivity. Radiographic sacroiliitis was observed in eight patients (6.2%) who revealed HLA B27 negativity. Both peripheral arthritis and sacroiliitis were found in six patients (4.6%). In CD, arthritis occurred in 20% of the patients with colonic involvement but in none of the patients without colonic involvement. In conclusion, arthritis was frequent in patients with IBD. Peripheral arthritis was more common in patients with UC than CD. All the patients with CD and arthritis had colonic involvement.