Colletotrichum gloeosporioides and Colletotrichum fioriniae are known pathogens of grape ripe rot. In 2010 and 2011, another Colletotrichum species was isolated from fruits of grape cvs. Sekirei and Pione with ripe rot symptoms in Yamanashi Prefecture. These isolates were identified as Colletotrichum nymphaeae based on morphological and molecular analyses. The ripe rot symptom was reproduced on grapevine fruits after inoculation with the isolates. C. nymphaeae was thus proved to be a new pathogen of grape ripe rot.