The material for the analyses comprised blood samples collected from 65 Zlotnicka Spotted (Zlp) sows and 43 Zlotnicka White (Zlb) sows born and kept in two herds in Wielkopolska. While analysing reproductive, fattening and slaughter traits, information was collected on 290 litters, including 180 litters of Zlp sows and 110 litters of Zlb sows. Intravital measurements were taken using a Piglog 105 for the evaluation of the mean backfat thickness, lean meat content and loin eye thickness. The aim of the research was to determine the effect of selected genotypes on reproductive, fattening and carcass performance traits of the two indigenous pig breeds (Zlotnicka White and Zlotnicka Spotted), kept and bred in Poland. The frequency of RYR1 genotypes indicates that the number of animals with the RYRTT genotype carrying a mutation in the RYR1 gene was low in the Zlotnicka breeds. In the herd of Zlb sows, a statistically significant negative effect of the RYRCT genotype on piglet wastage up to 21 days of age was found. The highest wastage rate was recorded in the group of heterozygotes. The frequency of the genotypes indicates that the DD genotype typical of animals with polymorphism in the GH/MspI gene occurred rarely in the analysed population of the Zlotnicka breeds. A statistically significant effect of the GH/MspI genotype on litter weight at 21 days of age was observed in the population of the Zlb sows. The heaviest piglets were born to sows with the DD genotype, while the lightest piglets were born to sows with the CC genotype. The frequency of the LEP genotypes indicates that the number of animals with the TT genotype was very low in the population of the Zlb pigs. No animal with the TT genotype was found in the Zlp herd.