In the USA, herbicides are widely used as an integral tool for weed management. With genetically modified crops such as Roundup Ready® (glyphosate-resistant) corn and soybean, herbicides that normally would have killed a crop can be used for weed control. Over years of use, some weed species have developed resistance to glyphosate and require novel approaches to management. New technologies, including 2,4-D and dicamba resistant crops, are one approach for corn and soybean farmers to better manage weeds; however, vapor or particle drift of these herbicides can damage sensitive crops such as grapes, tomatoes, and peppers. Research over the last 30 or more years has shown some of the effects of these herbicides on sensitive crops. With the impending introduction of new resistance traits in agronomic crops, the use of 2,4-D and dicamba will likely increase both in number of applications and in total volume applied per year per given area. Therefore, the severity and frequency of damage observed on sensitive crops may also increase. Grapes are an important crop in Ohio as fresh fruit and for wine production. The wine industry attracts millions of tourists each year with a measureable positive economic effect. With the predicted increase in use of 2,4-D and dicamba, grape growers are concerned about the potential for damage to their vineyards. This research was conducted to better understand the risk associated with this increased use. Grapes were extremely sensitive to 2,4-D and dicamba, to rates as low as 0.0028 kg ae/ha. A greenhouse study with varieties of grapes likely to be planted in Ohio over the next 10 years indicated that V. vinifera varieties were slightly more sensitive than hybrid varieties, showing greater injury symptoms, including leaf cupping (dicamba), chlorosis (glyphosate) and parallel venation, and fan shaped leaves (2,4-D). In a field study, the effects of timing (pre bloom, full bloom, and post bloom) and of rate (0.028, 0.0084, and 0.0028 kg ae/ha) of simulated 2,4-D and glyphosate drift were evaluated on `Riesling’ vinifera grape. Fruit yield and quality were measured in 2011 and 2012. In 2011, 2,4-D + glyphosate at 0.0084 kg ae/ha + 0.028 kg ae/ha caused effects on shoot length and visually observable injury symptoms, regardless of application timing. Symptoms of injury included parallel venation, fan shaped leaves, and, in more severely injured vines, death of new shoot growth. However, only 2,4-D + glyphosate at 0.028 kg ae/ha + 0.028 kg ae/ha applied pre and post bloom and 0.0084 kg ae/ha + 0.0084 kg ae/ha applied post bloom affected yield. Post bloom application of 2,4-D + glyphosate at 0.028 kg ae/ha + 0.028 kg ae/ha and 0.0084 kg ae/ha + 0.0084 kg ae/ha also resulted in a loss of yield in the year following the herbicide treatments. One year after application, some vines had died that were treated with post bloom 2,4-D + glyphosate at 0.028 kg ae/ha + 0.028 kg ae/ha and 0.0084 kg ae/ha + 0.0084 kg ae/ha. The application of the pre and full bloom 0.028 kg ae/ha + 0.028 kg ae/ha in 2012 caused much greater injury (96-100% injury) and loss of yield (100%) than in 2011. In conclusion, 2,4-D and dicamba drift may result in severe injury to grapevines; and the rate and timing of the drift can affect the severity of damage observed. The damage caused by the combination of 2,4-D and glyphosate was almost always more severe than either herbicide applied alone in the field.