Two South-West European populations (Galicia and Central Portugal) have been studied for the HLA DQA1 and D1S80 systems. The allele and genotype frequencies found have been compared with other previously published data. The distribution of the observed genotypes is in Hardy-Weinberg equilibrium for both systems. In the D1S80 system, no significant differences were found between both populations, although in the HLA DQA1 system the allele DQA1*0301 is twice as frequent in the Galician population. Other populations that have been compared showed a certain degree of divergence for the HLA DQA1 system. The combined chance of exclusion for both systems is 0.84 in Galicia and 0.85 in Central Portugal, and the combined power of discrimination is 0.993 in the 2 populations studied.