The aim of the research was to compare differences in lipid and protein oxidation, total iron content and fatty acid profile in pork loin obtained from organic and conventionally reared pigs. The samples of organic meat were taken from breeding certified by the polish certifying body according to the Council Regulation (EC) no 834/2007 on organic production and labelling of organic products. The meat samples were examined at the following times post-mortem: 2, 4, 7 days. Measurements of lipid oxidation showed that the organic meat samples were characterised by lower TBARS values during whole storage period (0.78–0.81 mg kg−1) compared with those of conventional system production (0.95–0.99 mg kg−1). Results of protein oxidation measurements of the organic meat sample were significantly lower (0.43 nmol mg−1 protein) at the beginning of experiment than those for the conventional meat sample (0.66 nmol mg−1 protein). It was also indicated that the production system had no effect on iron content and myoglobin oxidation during storage. In conclusion, obtained results pointed out that the organic pig meat was characterised by higher lipid stability during the whole storage time compared with meat from conventional production system.