Trichosporon asahii is a rare opportunistic infection, especially in children, causing a life threatening fungal infection underlying hematologic malignancies. Predisposing factors for infection with this pathogen are immunodeficiency including underlying malignancy, organ transplantation, extensive burns, human immunodeficiency virus infection, corticosteroid therapy, prosthetic valve surgery, and peritoneal dialysis. In the literature, a breakthrough under caspofungin, micafungin therapy is reported. In this article we report on a 16-year-old patient with Ewing sarcoma who had T. asahii sepsis. The patient died although he had been receiving caspofungin for less than 3 months and amphotericin B therapy for 3 days. A postmortem study of conchal tissues revealed T. asahii and mucormycosis histopathologically, and blood culture grew T. asahii. Copyright (C) 2013, Taiwan Society of Microbiology. Published by Elsevier Taiwan LLC. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).