Powdery mildew, caused by Erysiphe necator Schwein is one of the most important fungal disease of grapevine worldwide, including Syria. Although the application of chemical fungicides is the most common control method, the use of resistant varieties is considered the most effective and environmentally sound strategy for managing the disease. The aim of this study was to evaluate the susceptibility of five local grape varieties cultivated in southern Syria to powdery mildew under artificial inoculation. The results showed that young leaves, mostly from the first to the sixth leaf, were the most susceptible, whereas older leaves were resistant or less susceptible. The incubation period was relatively short and did not exceed three days in young leaves, whereas it reached 14 days in the older leaves. According to the assessment scale used in this study, “Salty” and “American” varieties were highly resistant (HR), “Halwani” variety was susceptible (S), whereas “Baladi” and “Aswad” varieties were highly susceptible (HS). This is the first report on variation in susceptibility of Syrian local grape varieties to powdery mildew, and the resistant varieties identified could have potential use by breeders as sources of powdery mildew resistance