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Podosphaera fusca (syn. Sphaerotheca fusca, S. fuliginea) is a causal agent of powdery mildew infections on Zinnia elegans, and has been documented in Korea since 1967. An outbreak involving about 1,000 plants in October 2008, in Yangpyeong, Korea, was caused by Golovino-myces cichoracearum. Further surveys of zinnia pow-dery mildew from 2008-2010 confirmed the widespread occurrence of Zinnia-Golovinomyces association in Korea. Chasmothecia of this fungus have not been found on Z. elegans in Korea. Analysis of internal transcribed spacer rDNA from five Korean collections confirmed the pow-dery mildew as G. cichoracearum. Comparison with the those from GenBank revealed 100 % identity with sequences from zinnia powdery mildew, forming a mono-phyletic clade with 100 % bootstrap support, and with those of G. cichoracearum parasitic on the hosts belong-ing to the tribe Heliantheae of the family Asteraceae