Sporothrix schenckii is a fungus known to cause infection of skin in the subcutaneous tissues. In this case tenosynovitis was caused by sporotrichosis resulting in rupture of the extensor tendon. Excision of the involved tenosynovium and repair of the tendons were done. Five months of oral medication with ketoconazole, 400 mg daily, led to resolution of the synovial disease and regression of a 1 cm pulmonary nodule found on a routine chest x ray film. © 1986, American Society for Surgery of the Hand. All rights reserved.