The aim of the study was to determine the fatty acid composition of some selected pistachio types, two domestic pistachio cultivars (Uzun and Siirt), four Iranian cultivars (Ohadi, Vahidi, Mumtaz and H. Serifi) and an American cultivar (Kerman). The fat content of pistachio seeds ranged from 35.38% (Mumtaz) to 51.68% (Sel-5). The fatty acid composition was determined after harvesting. The fatty acid composition of the pistachio genotypes ranged from 7.45-10.14% saturated fatty acids (SFAs), 55.23-77.61% monounsaturated fatty acids (MUFAs) and 13.82-33.11% polyunsaturated fatty acids (PUFAs). The unsaturated/saturated fatty acid ratio varied between 8.74 and 12.34.