A 32-year-old woman in the 36th week of pregnancy was admitted to obstetrics with a complaint of left flank pain. Magnetic resonance imaging demonstrated a left perinephric hematoma before the cesarean section. Spontaneous rupture of renal angiomyolipoma was suspected by computed tomographic scan and renal angiography after the cesarean section. We attempted partial nephrectomy, but performed nephrectomy because of perinephric adhesion. This is the 11th case of spontaneous rupture of renal angiomyolipoma during pregnancy in the Japanese literature.