Twenty-seven (CA)n and two (GA)n microsatellite clones were isolated out of a size-selected genomic pig library. These were sequenced and the number of uninterrupted dinucleotides was found to range from 12 to 26. Flanking primers were chosen for 11 dinucleotide repeats and optimal conditions for polymerase chain reaction (PCR) amplifications were established. Different microsatellite loci were amplified simultaneously by combining primer sets. Related and unrelated pigs were screened for length polymorphisms of the different microsatellite loci. The polymorphic information content (PIC) of these loci ranged between 0.62 and 0.83. Segregation studies in pig reference families established Mendelian inheritance. Locus S0022 was found to be X-linked.