Spindle cell rhabdomyosarcoma, a recently described variant of embryonal rhabdomyosarcoma in children, carries a favorable prognosis when compared with other types of rhabdomyosarcoma. This tumor is rare in adults, and only four cases have been documented previously. The clinicopathological study of such a case occurring in the retroperitoneal space of a 53-year-old man is herein reported. The patient died of uncontrolled local recurrence and hepatic metastases seven months after diagnosis. Based on the analysis of the data of the five cases reported, including the present one, it can be stated that spindle cell rhabdomyosarcoma in adults is not associated with the favorable outcome observed in the pediatric population.