Separate databases were made for all pig and chicken sequences in the Genbank database, which were then systematically searched for all possible mononucleotide, dinucleotide, trinucleotide, and tetranucleotide repeats of about 20 bp or greater in length. A total of 13% of pig genes and 10% of chicken genes contained one or more of these microsatellite-like repeats. There was a considerable difference in the frequency of dinucleotide repeats between pigs, where they comprised 30% of the repeats found, and chickens, where they comprised only 12%. The AC/GT category displayed the greatest difference: seven cases were found from 181 genes in pig (3.9%), whereas only five were found from 531 genes in chicken (0.9%). There appears to be a substantial difference in the spectrum of microsatellites between pigs and chickens. Primer sequences for amplifying these microsatellites are presented.