Allele and phenotype frequencies for the YNZ22 locus were determined in a population sample from Catalonia (Spain) using the polymerase chain reaction (PCR). In 311 unrelated individuals, 14 alleles and 56 phenotypes were observed. No deviation from Hardy-Weinberg equilibrium was found. The observed heterozygosity was 81.35%. The YNZ22 polymorphism is useful for paternity testing with a CE value of 70% and an Essen-Möller value of 9.35 (log.).