Adinandra nitida leaf extract (ANE) is rich in phenols and flavonoids. In this study, the effects of ANE as an additive on the formation of major heterocyclic amines (HCAs), namely, PhIP, norharman and harman, in both chemical model systems and fried chicken patties were explored. In model systems, treatment with various amounts of ANE (0, 15, 30, 45, 60 mg) led to the most effective inhibition of PhIP, norharman and harman, with levels reduced by 47.88%, 49.73% and 29.63% when treated with 45 mg, 60 mg and 60 mg, respectively. Further, the effect of diverse dosages of ANE (0, 0.2, 0.4, 0.6%, w/w) on the formation of HCAs in chicken patties fried at 170 °C and 190 °C was evaluated. Statistics showed that the temperature significantly increased the formation of HCAs. Total HCA contents of patties fried at 170 °C and 190 °C ranged from 1.52 ng g⁻¹ to 2.52 ng g⁻¹ and from 6.05 ng g⁻¹ to 13.76 ng g⁻¹, respectively. The inhibitory efficacy of various concentrations of ANE on the total HCA content was higher (38.95–56.03%) in patties fried at 190 °C than at 170 °C (18.65–40.08%). External parts of the meat patties showed higher HCA contents than the interior. The current study presents evidence that ANE at moderate dosages can reduce the formation of HCAs in fried chicken. By extension it suggests that ANE has potential applications as a natural antioxidant for preventing the formation of HCAs in foods.