We report a case of a 61-year-old woman who underwent hip arthroscopy for a labral tear. The acetabular labrum was resected arthroscopically. Three months later, magnetic resonance imaging showed avascular necrosis of the femoral head. Theoretically, avascular necrosis following hip arthroscopy may result from traction on vessels supplying the femoral head, direct injury to such vessels during portal entrance, raised intra-articular pressure, prolonged operating time and damage to vessels during bony resection or osteochondroplasty for femoroacetabular impingement. We presume that avascular necrosis in our case was a result of a traction injury and increased intra-articular pressure.