Nuts are energy-rich foods with nutrients like monounsaturated and polyunsaturated fatty acids, high-quality proteins, fiber, minerals, tocopherols, phytosterols, and antioxidants. These components improve metabolic pathways and vascular physiology. Nut consumption is linked to a lower cancer incidence, improved cognitive function, and reduced depression and cholesterol. Nuts can be considered natural pleiotropic nutraceuticals. Their nutritional and functional composition is strongly influenced by environmental conditions. In the last decade, there has been a significant increase in the cultivation of walnuts and pistachios in the Mendoza and San Juan provinces (i.e., the Cuyo region), which have different agroclimatic conditions from the traditional growing areas. This study evaluated the impact of environmental conditions on the fatty acid profile and proximate composition of nuts from the Cuyo Region. Chandler-variety walnut samples were obtained from two farms in Mendoza, while Kerman-variety pistachios were recollected from San Juan. On each farm, three blocks were randomly selected, each with three adjacent trees with similar fruit load and crown size. Each block corresponded to contrasting environmental conditions (soil and altitude) within each farm. The proximate composition varied across the nuts evaluated. The highest moisture content, fiber, and carbohydrate content were found in pistachio. The total lipids content ranged from 44.5 to 68.1 g of oil per 100 g⁻¹ dry solids for walnut and pistachio, respectively. The identification of fatty acids was carried out using gas chromatography–mass spectrophotometry. The most abundant fatty acids in walnut were linoleic acid (63.36 %), linolenic acid (17.18 %), and cis oleic acid (11.04 %), while cis oleic acid (56.70 %), linolenic acid (27.15 %), and palmitoleic acid (11.13 %) were the dominant fatty acids in pistachio. The results did not show variability in fatty acid concentrations between blocks (p<0.05). This information provides insights into the fatty acid profiles and compositions of nuts from two new production areas.