BackgroundLeiomyomas are benign tumors observed mainly in adult women. The retroperitoneum is a rare location for leiomyomas; almost 100 cases have been reported. Because retroperitoneal leiomyomas are paucisymptomatic and the tumor size at diagnosis is relatively large, surgical management is challenging. Regular follow-up is required because recurrence and malignant sarcomatous transformation have been described in a few cases.Case presentationWe report a case of a 52-year-old North African woman with a 22-cm retroperitoneal leiomyoma. A preoperative embolization was performed 2 days before surgery. The clinical, therapeutic, and evolutive aspects of this rare entity are discussed.ConclusionsDespite its benignity, retroperitoneal leiomyoma is a challenging diagnostic, therapeutic, and evolutive condition. Surgeons must consider mainly the tumor’s vascularization. Regular follow-up is mandatory because malignant transformation cannot be excluded.