Atlas pistachio fruits are an important source for pharmaceutical uses and human health. However, its chemical composition has not been sufficiently exploited previously. This study, explores the characteristics and chemical composition of the fruit oil of three populations of Pistaciaatlantica Desf. subsp. atlantica grown in three different zones in Algeria (Tiaret T-R, Tiaret T-Z and Laghouat). The oil content has ranged from 50.5 to 67.3% registered in Tiaret (T-R) and Laghouat, respectively. Moreover, the acid index and peroxide value highlighted mean values about of 8.98–25.8 mg KOH/g oil and 0.6–1.4 meq O2/kg oil respectively. The determination of fatty acids composition by gas chromatography showed that this species is mainly rich in unsaturated fatty acid (UFA). The limited values of UFA are 74.4 for Tiaret (T-R) and 76.4% for Laghouat. Its main compounds were oleic (39.1–49%), linoleic (23.6–31%) and palmitic (21.3–23.6%) acids. Also, the β-sitosterol is the main composant of phytosterols which is largely abundant in the extracted oil where its value exceeded 72.8 mg 100 g−1. In summary, the fruit oil of Atlas pistachio is mainly rich in UFA and sterol, which take an important place in several fields. Therefore, it will be important that this species could be exploited in Algeria.