Anteroposterior (AP) x-rays provide limited information about size and location of acetabular osteolytic lesions after total hip arthroplasty (THA). In the study reported here, we sought to determine the utility of oblique (Judet) x-rays in preoperative assessment of acetabular lesions. AP, anterior (obturator), and posterior (iliac oblique) x-rays of 10 patients (10 hips) who underwent revision THA were evaluated retrospectively. Mean osteolytic area was 790 mm2 (SD, 520 mm2) on anterior oblique x-rays and 384 mm2 (SD, 396 mm2) on AP x-rays (P = .005). Mean osteolytic area on posterior oblique x-rays was 512 mm2 (SD, 430 mm2) (P = .34). Judet x-rays were useful in determining size and location of acetabular osteolysis.