Caspofungin is an antifungal medication proved efficacious and well-tolerated in adults. Twenty-five pediatric patients at St. Jude Children's Research Hospital who had received at least one dose of caspofungin were identified, and their records were reviewed retrospectively. Caspofungin was well-tolerated; only three patients experienced any adverse event judged possibly related to drug. Caspofungin appears to be safe in immunocompromised pediatric patients.