Introduction: Female urinary retention is rare. Case presentation: Case 1, a 35-year-old nulliparous woman, and case 2, a 47-yearold nulliparous woman, had transient urinary retention. A urodynamics revealed increased bladder sensation in case 1 and detrusor underactivity with a large post-void residual in cases 1 and 2. Both women had a uterine leiomyoma of >10 cm in diameter. Soon after extraction of the tumor, retention episodes disappeared completely in case 1. Conclusion: Although rare, uterine leiomyoma should be listed as a cause of female detrusor underactivity.