A retroperitoneal angioleiomyoma was incidentally detected in a 56-year-old woman during an examination of cardiovascular disease, and referred to the department of urology. Computed tomography (CT) showed a solid tumor approximately 3 cm in diameter, enhanced heterogeneously adjacent to the right adrenal and renal vein on magnetic resonance imaging the tumor showed a low intensity in the T1-weighted image and high intensity in T2-weighted image. These radiographic findings suggested a retroperitoneal tumor such as paraganglioma, angioma. Furthermore, because she was a carrier of Human Adult T Cell Leukemia Virus-I (HTLV-I) this tumor was suspected to have relevance to malignant lymphoma. We performed laparoscopic surgical excision of the tumor. Pathlogical diagnosis was an angioleiomyoma. Angioleiomyoma is a rare type of leiomyoma originating from smooth muscle and containing thick-walled vessels. Only a few cases of retroperitoneal angioleiomyoma have been reported.