A 29-year-old primigravida was admitted to the urology ward with acute urinary retention. The patient underwent cystoscopy, MRI (magnetic resonance imaging), and tissue biopsy, which consequently led to the diagnosis of bladder neck leiomyoma that obstructed urine outflow. Subsequent to a cesarean section, a successful transurethral resection was performed. Here the diagnostic complexity in the pregnant patient, clinical course, and outcome are described. One year after successful treatment both mother and daughter are in good condition.