This study was carried out to determine the efficiency of electrophoretic methods in predicting graft incompatibility of grape cultivars with American rootstocks. Three isoenzyme systems (peroxidase, PER; esterase, EST; acid phosphatase, AcPH) and total protein profiles were obtained in 15 Grape cultivars (Vitis vinifera L.) and 12 American rootstocks. Compatibility levels were determined by the band similarities. Field compatibilities were also calculated. Results showed that incompatibility exists between different cultivar-rootstock combinations. AcPH and total protein profiles of the cultivar-rootstock combinations could be suggested to use for forecasting graft incompatibility. (c) 2007 Published by Elsevier B.V.