Since processing may affect the quality and benefits of foods, a study was conducted to compare some properties of fresh, sun-dried (constant water content of 4%) and oven-roasted (130 °C for 25 min) pistachio nuts of two cultivars. Carotenoid, iron, copper, manganese, total saturated, total unsaturated, palmitic, and linolenic fatty acids showed no statistical difference (P≤0.05) among the samples. Comparing the ‘Akbari’ cultivar, the ‘Ahmadaghaei’ cultivar had less anthocyanin and less palmitoleic acid. Drying and roasting reduced antioxidant activity, flavonoid content, and arachidonic acid while increasing kernel firmness, malondialdehyde, and hydrogen peroxide. Chlorophyll content was higher in dried and roasted than fresh status in both cultivars. Stearic acid had a stable content in ‘Ahmadaghaei’, but increased by drying and roasting in ‘Akbari.’ Oleic acid increased by drying and roasting in ‘Ahmadaghaei.’ In ‘Akbari,’ oleic acid first decreased by drying and then increased to the initial level by roasting. Linoleic acid decreased by drying and roasting in ‘Ahmadaghaei’. In ‘Akbari’, it revealed an increasing trend by drying, but again decreased to the initial content after roasting. In conclusion, the conditions in this experiment for drying and roasting the pistachios were not harmful and had some advantages, leading to better pistachios storage.