Invasive aspergillosis is uncommon in immunocompetent hosts but is the second most common opportunistic fungal infection in immunocompromised patients. There has been a dramatic increase in the incidence of life-threatening aspergillosis during the past 2 decades, and the morbidity and mortality of these infections despite antifungal therapy remain unacceptably high. We describe a patient with amphotericin B-resistant Aspergillus flavus successfully treated with caspofungin, an agent belonging to a new class of antifungal drugs. Caspofungin shows great promise in the treatment of invasive aspergillosis. (J Am Acad Dermatol 2002;46:945-7.)