In this report, a case of leiomyoma in urinary bladder of a 5 years old. male. Kangal dog was described. The dog was presented with clinical complains of hematuria, stronguria and prolapsus penis. Clinical and radiograph ical findings signed a mass in urinary bladder. Erytrocytes, leucocytes and urine crystals were observed in urine samples. Surgically removed tumoral mass was 3x4x6.5cm in diameter, hard and whitish-pink coloured. His-topathologically tumor diagnosed as leiomyoma. Corynebactenum spp. was isolated from urine in postsurgical period.