The effect of adding pink pepper (Schinus terebinthifolius Raddi) fruits during sardines canning to minimize cholesterol oxidation were investigated. Canning resulted in an exchange of fatty acids, cholesterol and cholesterol oxides between fish muscle and liquid medium (soybean oil). It also induced lipid oxidation, which was demonstrated by the degradation of fatty acids and the formation of cholesterol oxides. Cholesterol oxides increased from 39.53 ± 2.14 μg/g (raw sardines) to 116.04 ± 0.78 μg/g (control sardines) after canning. However, lower levels were found in samples with pink pepper. Additionally, chromatographic analyses showed the migration of compounds (phenolic acids, flavonoids, tannins, terpenes) from pink pepper to sardines, indicating the constituents that could have contributed to its antioxidant properties. Thus, pink pepper may be highlighted as a suitable additive to reduce the intake of cholesterol oxides, minimizing the loss of nutritional quality in canned fish.