We report a case of a 27-year-old man with pigmented villonodular synovitis of the hip joint with coincident osteonecrosis of the femoral head. According to our review of the English-language literature, no detailed report of osteonecrosis of the femoral head complicated with pigmented villonodular synovitis has been published. Preoperative X-ray images showed joint narrowing and severe multiple bone erosions at the acetabulum and femoral neck. Magnetic resonance imaging revealed a low-intensity band attributable to osteonecrosis of the femoral head and massive diffuse pigmented villonodular synovitis lesions. Comparison of a three-dimensional computed tomographic image of this patient with an angiographic image of a normal individual demonstrated proximity of the pigmented villonodular synovitis-induced bone erosions to the medial and lateral femoral circumflex arteries and retinacular arteries, suggesting likely the compromise of the latter by the former. We propose that the massive pigmented villonodular synovitis may have contributed to the pathogenesis of osteonecrosis of the femoral head in this patient. We performed open synovectomy and total hip arthroplasty. No operative complications occurred, and no recurrence of the pigmented villonodular synovitis was detected for 3 years after the operation.