Infections of deep soft tissues with the dimorphic fungus Sporothrix schenckii are uncommon in humans, and therapy has often required toxic drugs. We report our experience in treating 11 patients who had deep-seated sporotrichosis with ketoconazole, a well-tolerated, orally absorbed antifungal agent. Eight infections involved one or more joints, and three involved thoracic, cervical, and widespread cutaneous sites, respectively. For eight patients all evidence of infection resolved during therapy. Sustained remissions (6 months to 5 years) were noted for six patients after the discontinuation of all therapy and for an additional patient 4 years after the initiation of ketoconazole treatment. Durable responses were associated with prolonged treatment with 400-800 mg of ketoconazole daily. Our favorable experience suggests that oral therapy with ketoconazole may benefit other patients with systemic sporotrichosis.