<p>Grapevine geminivirus A (GGVA) is a recently identified DNA virus that infects grapevine, but its pathogenicity is not well studied. Previously, we investigated the pathogenicity of the new GGVA isolate QN (GGVA^QN) on grapevine ‘Red Globe’ plants. In this study, grapevine ‘Red Globe’ and ‘Summer Black’ plants were inoculated with GGVA^QN and grown without artificial control of temperature and light, and all of them exhibited upward leaf curling. This symptom was also found in field-grown grapevine ‘Shine Muscat’ plants infected with multiple grapevine viruses, including GGVA (isolate SM) (2,905 nt, sharing 97.69% genome sequence identity with GGVA^QN), and in the upper developed leaves of previously GGVA^QN-inoculated ‘Red Globe’ plants one week after they were moved from artificial to natural lighting. The upward leaf curling symptom was similar to that observed previously in <i>Nicotiana benthamiana</i> plants inoculated with GGVA^QN, in field-grown grapevine ‘Queen Nina’ plants, and in <i>in vitro</i>-grown grapevine ‘Marselan’ plantlets, from which GGVA^QN and GGVA^ML isolates with identical genome sequences were obtained. In addition to upward leaf curling, malformation, chlorosis, and necrosis symptoms were also observed on all GGVA^QN-inoculated ‘Red Globe’ and ‘Summer Black’ plants. The findings presented here suggest that GGVA^QN is closely associated with severe foliar symptoms in grapevine ‘Red Globe’ and ‘Summer Black’ cultivars and emphasize the need to control the virus.</p>