We present a rare case of leiomyoma of the urinary bladder that was diagnosed during pregnancy. To our knowledge, this is the fourth case of its kind to be reported in the literature. Ultrasonography, magnetic resonance imaging and biopsy were useful for making an accurate diagnosis in this case. The diagnosis was confirmed by suprapubic transcutaneous needle biopsy. The tumor was resected approximately 3 years after diagnosis, during which period the patient delivered a normal baby by caesarian section.