Characteristic roentgenographic patterns of femoral head migration occur in osteoarthritis of the hip. In a study of 100 patients superolateral migration was noted in 15, superomedial in 48, superior migration of intermediate type in 15, and medial displacement of the femoral head in 22. Correlation with pathologic specimens obtained following total hip replacements and comparison with patterns of femoral head migration in rheumatoid arthritis were accomplished. It would appear that anatomic features of the acetabulum are of prime importance in the determination of the type of femoral head displacement complicating osteoarthritis.