Blastomycosis, endemic in North America, has been hardly reported in Korea. We describe laboratory experience in phenotypic and molecular identification of Blastomyces dermatitidis first isolated in Korea. The patient was a 45-year-old male with pulmonary blastomycosis mimicking pulmonary tuberculosis. Diagnosis was based on culture and dimorphism combined with DNA target sequencing of internal transcribed spacers (ITS) and D1/D2 regions. (Korean J Clin Microbiol 2012;15:114-116)