Abstract Peach (Prunus persica) is one of the most valuable fruit trees around the world including Iran. During spring and summer 2016, severe branch dieback and canker was observed on peach trees in Hamadan province, Iran. The cankered peach twigs contained fruiting bodies of the fungus. It was estimated that 58% of peach trees were severely damaged by this disease. A fungus was consistently isolated from infected tissues. Morphological and cultural characteristics, as well as the sequences of the ITS and β-tubulin regions and pathogenicity tests, showed that the causal agent of disease was Cytospora chrysosperma. It was already reported that C. chrysosperma caused severe losses on a wide range of plant hosts worldwide. However, to our knowledge, this is the first report of C. chrysosperma on P. persica in the world and Iran
