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 radiographical lindings signed a mass In unnary bladder. Erytrocytes, leucocytes and urine crystals were observed in unne samples. Surgically removed tumoral mass was 3x4xS.Scm in diameter, hard and whitish-pink coloured. Histopathologically tumor diagnosed as leiomyoma. Corynebacterium spp. was isolated from urine in postsurgical period.