Retzius space is a small anatomical compartment located directly posterior to the pubic symphysis and anterior to the urinary bladder. Diseases developing primarily in this space are rare; only 7 cases of leiomyomas of the Retzius space have been reported in the literature so far, all of them in female patients. We present a unique case of a leiomyoma of the Retzius space in a male patient. An imaging‐based diagnostic approach to Retzius space disease is proposed.