A case of postpartum spontaneous rupture of angiomyolipoma in a 27-year-old woman with the chief complaints of right flank pain and fever was reported. Physical examinations revealed an infant-head sized, hard elastic mass with a smooth surface in the right flank. Laboratory studies showed a decrease of Hb to 9.0 g/dl and Ht to 26.5%, and elevated LDH (2914 IU/l). Angiomyolipoma was suspected with ultrasonography, CT scan and angiography. Transperitoneal right nephrectomy was performed. The right kidney and tumor weighed 1,870 g. Pathological diagnosis also confirmed angiomyolipoma of the kidney. Discussion of the case and a brief review of the literature on spontaneous rupture of angiomyolipoma in the intra- and postpartum are made.