Abstract. The aim of this study was to investigate, if special genotypes of the genes glutathione peroxidase 5 (GPX5), fucosyltransferase 1 (FUT1) and estrogen receptor 2 (ESR2) are associated with litter size in a commercial pig cross population. For this purpose, a total of 123 F₂ sows were divided into two extreme performance groups, one with a high litter size (n = 61, ≥ 14.3 piglets per litter) and one with a low litter size (n = 62, ≤ 11.3 piglets per litter) and genotyped using PCR-RFLP methods. The Chi-square test was used in order to investigate, if a special genotype occurs significantly more often in one of the two performance groups (p < 0.05). Whereas no association was found between different ESR2 or GPX5 genotypes with one of the two performance groups, the number of sows with AB genotypes at the FUT1 gene was significantly increased in the high performance group in comparison to the low performance group.