Allele and genotype frequencies for 2 short tandem repeat loci were determined in a population sample from Catalonia (Spain) using the polymerase chain reaction. After denaturing PAG electrophoresis, seven common and one variant (13.3) alleles were identified for HUMTH01 in a sample of 234 unrelated individuals, and seven alleles were found for HUMVWA31A in 162 individuals. No deviation from Hardy-Weinberg equilibrium was found. The observed heterozygosities are 76.92 and 79.62 respectively. The discrimination power determined for the individual loci is 0.928 and 0.937 respectively.