The distal part of the porcine chromosome 7 which contains the orthologue to the ovine region encompassing the callipyge locus was analyzed in a Pietrain F(2) resource population comprising more than 2,700 offspring. The aim of the study was to map quantitative trait loci (QTL) affecting carcass traits comparable to the callipyge phenotype in sheep. We applied an interval mapping approach using 14 microsatellite markers and detected three QTL with small effects. The first QTL affects fat thickness on the middle of the back with no detectable impact on fat-sizes at other places on the back, another affecting side fat thickness. The third QTL influences the ham weight and shows a clear parent-of-origin-dependent effect in the form of maternal polar overdominance. It is not located at the position of the imprinting cluster including the callipyge locus but 7 cM proximal.