Abstract: Pistachio (Pistacia vera) is a edible nut native to Iran, the country that ranks first in worldwide pistachio production. Root-knot nematodes (RKN), Meloidogyne species, are among the most important pathogens that restrict the cultivation of pistachio in Iran. The objective of this study was to evaluate resistance of native pistachio rootstocks for resistance to isolates of M. incognita. Greenhouse experiment was conducted to determine the reaction of eleven cultivars of P. vera and six accessions of wild pistachio viz P. mutica, P. khinjuk, P. terebintus, P. atlantica, P. atlantica sub sp mutica and P atlantica sub sp cabilica, against five selected populations of RKN. Meloidogyne incognita andM. javanica were identified based on the morphological characters, and esterase isozyme phenotype. Resistance was characterized based on root gall and egg mass indices and nematode reproduction. Resistance to M. incognita was detected among the cultivars and wild accessions of pistachio. There was a significant interaction among nematode populations and host genotypes, suggesting the presence of virulent pathotypes among the M. incognita isolates. These data suggest that it will be possible to development cultivars with resistance as a means of suppressing damage to pistachio that is caused by RKN.