Sporotrichosis was diagnosed in five cats. Seven humans exposed to these cats subsequently developed the disease. All feline cases developed draining ulcers, and in four of five cases there was disseminated cutaneous involvement. Histologically, numerous Sporothrix organisms were noted in cutaneous lesions and overlying exudate. The seven humans who became infected were involved in cleaning and medicating cats with the disease; all human patients developed a localized lymphocutaneous form of sporotrichosis. In four of the human cases there was no history of an associated penetrating wound. The large number of Sporothrix organisms is a distinct feature of feline sporotrichosis and indicates that the cat may be the only domestic animal species that can readily transmit this disease to humans. In addition, any contact with the draining lesions of affected cats offers the potential for human infection.