Beta 2-microglobulin amyloid deposition is associated with a destructive arthropathy in the hip of chronic hemodialysis patients. Twenty-five hips from 18 patients were assessed for the presence and immunohistochemical type of amyloid. The hemodialysis group was compared with an age- and disease-matched control group that had no evidence of renal failure. Beta 2-microglobulin amyloid deposits were present in all patients who had been on hemodialysis for 18 months or more. Beta 2-microglobulin amyloid deposits were not found in patients who had been on hemodialysis for less than 18 months. Amyloid deposits were seen first in the articular cartilage and later involved the synovial membrane, joint capsule, and subchondral bone as well. The presence and amount of amyloid deposition correlated to the duration of hemodialysis. Severely affected hip roentgenographically had a concentric loss of joint space, periarticular erosions, and cystic lesions in the femoral head and acetabulum. These pathologic and roentgenographic changes suggest that amyloid deposition leads directly to the erosive hip arthropathy occurring in hemodialysis patients.