Erosive hip lesions are uncommon in patients with ulcerative colitis. We analyzed features of chronic hip lesions in four ulcerative colitis patients seen over the last 30 years. Two patients also had axial disease. Both hips were involved in all four cases. Roentgenographic features resembled those seen in ankylosing spondylitis in two cases. Severe destruction occurred in two patients. Two patients developed acetabular protrusion. All four patients rapidly required total hip arthroplasty, illustrating the poor prognosis of hip lesions associated with ulcerative colitis.