Primary transitional cell carcinoma(TCC) of the bladder is a rare during child-bearing age and only 10 such cases have been reported in the literature^1-6). The patients presented with gross hematuria which was initially mistaken as vaginal bleeding. Initial diagnosis was made with sonography. Diagnosis was easily confirmed by cystoscopy with biopsy. Transurethral resection of the bladder tumor was performed as usual manner and postoperative course was uneventful. We experienced transitional cell carcinoma of bladder in a 26 year-old in the 21 week of pregnancy.