The LMX1A gene, located within the 3.3 cM FAT1 QTL on porcine chromosome 4, was tested as a positional and functional candidate for fatness traits. A gene fragment consisting of the partial promoter, 5’UTR, exon 1, and partial intron 1, was sequenced in a panel of 79 pigs of Polish Large White (PLW), Polish Landrace (PL), Duroc and Pietrain breeds. Only a G to A substitution in intron 1 (182 bp upstream of the translation start site) was found. In total, 738 gilts were genotyped: 191 PLWs, 249 PLs, 239 of synthetic line 990 (L990), 21 Pietrain and 38 Duroc. The genotype distributions appeared to be breed-specific. Association studies were performed for 12 growth and fatness traits in the PLW, PL and L990 pigs and no association was found. The only result which approached the significance level (P=0.047) concerned the lean meat content. Our results indicate that the LMX1A gene should not be considered as a candidate gene for QTL in the FAT1 region in the studied Polish pig breeds.