This study aimed to analyze the phytochemical composition of rosehip fruits growing naturally in the Tuzluca district of Iğdır province, Türkiye. Rosehip, a species within the Rosa genus of the Rosaceae family, is a valuable plant with diverse applications in healthcare due to its unique phytochemicals. To investigate fruit characteristics, phytochemical properties, and antioxidant capacities, this study was conducted in 2018 across three villages in the Tuzluca district: Pirli (935 m), Hamurkesen (1830 m), and Ortabucak (1670 m). Organic acid analysis revealed the presence of fumaric acid (2.721–7.88 mg/100 g) and acetic acid (43.45–118.63 mg/100 g), while tartaric acid and succinic acid were not detected. Regarding phenolic compounds, chlorogenic acid (5.265–19.836 mg/100 g), catechin (277.88–597.4 mg/100 g), quercetin (1.5034–4.3187 mg/100 g), p-coumaric acid (0.157–3.488 mg/100 g), transferrulic acid (1.9037–6.2091 mg/100 g), and o-coumaric acid (3.7006–18.716 mg/100 g) were identified. Syringic acid, vanillic acid, caffeic acid, and gallic acid were not detected. In terms of sugars, fructose (0.307–6.188 mg/100 g) and glucose (0.137–5.263 mg/100 g) were present, but sucrose was not detected. Vitamin C content ranged from 599.8 to 863.81 mg/100 g, and the antioxidant capacity, measured as TEAC, was between 83.46 and 144.84 mg/100 g. This study represents a pioneering effort in the region, offering valuable insights into the phytochemical composition of locally grown rosehip fruits.