Assessing factor affecting Iranian Pistachio export due to comparative advantage and share of Iran in international market of this crop is very important. In recent years, pistachio exports has faced many challenges including limitation of aflatoxin maximum of importing countries. In the present study, factors affecting on Pistachio export with emphasis on the role of aflatoxins were evaluated by gravity model. For obtained this goal, the major importing countries pistachio were determined and panel data from the years 1990-2017 were used. The results of gravity model estimation showed that the limitation of aflatoxin, GDP, population and border for selected importing countries has significant positive effect on the export of Iran Pistachio. The result suggested that Iran to maintain it is share in the Pistachio global market, pistachio with high quality and lesser aflatoxin have to be product, as well as, sanitation laws are approved based on international laws could be very useful.