Candida orthopsilosis is a recently described Candida species phenotypically indistinguishable from Candida parapsilosis. This new species can be identified only by using molecular methods. We describe here a fatal case of fungemia caused by C. orthopsilosis in a 75-year-old male patient who had panperitonitis after total gastrectomy with Roux-en-Y esophagojejunostomy. All 18 blood cultures obtained from admission day 16 to day 68 yielded the same Candida species. Both Vitek 2 (bioMerieux, Inc., Hazelwood, MO, USA) and API 20C (bioMerieux, Marcy-l’Etoile, France) failed to identify these isolates. However, DNA sequencing analysis of both D1/D2 domain and internal transcribed spacer region of rDNA showed 100% identity with C. orthopsilosis. The fungemia was persistent over 50 days despite of systemic antifungal therapy including fluconazole and caspofungin, and the patient expired on day 73 of his hospital stay. This represents the first reported case of fatal fungemia by C. orthopsilosis in Korea. (Korean J Clin Microbiol 2010;13:140-143)