Pork offal are classified as edible by-products of meat derived from slaughtered animals. Owing to a high content of iron, vitamins, and high-valued proteins, pork offal may also be valuable components of food dishes. The objective of the research study was to determine the effect of genetically determined stress susceptibility/resistance of Pulawska breed fatteners on some physical and chemical parameters of the selected offal: tongue, kidneys, lungs, liver, and heart. The analyses were conducted on a group of 80 Pulawska breed fatteners (40 fatteners of C/C genotype at RYR1 locus and 40 fatteners of C/T genotype at RYR1 locus). The polymorphism of RYR1 gene was determined using a PCR-RLFP method. In the offal, the following was determined: pH (pH₄₅, pH₂₄); percent content of free water as well as the contents of protein, fat, and mineral compounds in the form of ash. The liver derived from the carcasses of fatteners with the C/T genotype was characterized by the lowest value of pH₄₅ (6, 10) whereas the lungs derived from the fatteners in the group of homozygotes that were not stress-sensitive (RYR1 C/C) were characterized by the highest pH₄₅ value (6.52). 24 hours after slaughter, pH of offal decreased and ranged from 5.68 to 6.10. The content of protein in the elements analyzed was from 12.97 % in the lungs of fatteners with the C/C genotype to 19.73 % in the liver of the C/T genotype). Statistically significant differences (p ≤ 0.05) were reported between the genotypes of the animals as regards the content of fat in the heart, lungs, and kidneys. In the above listed offal of the fatteners with the C/T genotype, the content of fat was found to be significantly (p < 0.05) lower compared to the fatteners having the C/C genotype. Differences (p ≤ 0.01) in the fat content in livers of animals with the C/C genotype (8.11 % ) and C/T genotype (5.62 %) were significant at (p < 0.05).