A case of disseminated trichosporonosis associated with Candida infection of the urinary bladder is presented. Coffee bean shaped or crescent shaped yeast-like elements are characteristic of Trichosporon and useful in differentiating Trichosporon from Candida but such histological features are less efficient than the immunohistochemistry in identifying mixed fungal infection. In the present case, an application of avidin-biotin-complex (ABC) method with anti-Trichosporon antiserum and anti-Candida antiserum enabled us to diagnose a mixed infection by both fungi.