Purpose: The aim of this study was to improve yield, and characteristics of pistachio nuts of three cultivars by foliar application of volk oil and potassium nitrate. Research method: The study was carried out during the bud swelling stage using a factorial design, following a randomized complete block design with four replications. The experimental factors consisted of three cultivars, namely 'Fandoghi', 'Hasan-Abbasi', and 'Haj-Abdollahi', and three treatments: volk oil (1% and 2%), potassium nitrate (KNO3) (0.3% and 0.5%), and a mixture of volk oil and KNO3 (1% volk oil + 0.3% KNO3, and 1% volk oil + 0.5% KNO3). A control treatment was also included in the study. Findings: The results of this study showed that the highest percentage of open shell nuts (52.17%) was observed in ‘Hasan-Abbasi’ cultivar, and the highest fresh weight of 100 nuts in ‘Haj-Abdollahi’ (202.2 g). The lowest ounce (29.07), the highest dry weight of 100 nuts and 10 kernels weight were obtained 76.26 and 26.56 g in ‘Fandoghi’ cultivar, respectively. The use of 2% volk oil treatment was effective in budbreaking, as well as increasing the percentage of open shell nuts and reducing the percentage of balk nuts. Research limitations: There was no limitation. Originality/Value: 0.5 % KNO3 increased the fresh and dry weight of 100 nuts and decreased ounce of pistachio in all cultivars. Therefore, the use of volk oil and KNO3 treatments can be effective in pistachio orchards, and increase the quantity and quality of the yield.