The Rio de Janeiro database was established for the three loci. The results of independent testing support the use of these data for estimating the matching probability of a DNA profile that contains these three STR loci. Ninety-seven unrelated individuals were genotyped for the 3 loci. Alleles already described for these loci were found in the Rio de Janeiro sample population. Eleven alleles were found for each of 2 loci (D8S1179 and D12S391), and 8 alleles were found for locus D7S820. All three loci are highly polymorphic in the sample population, and no detectable departures from Hardy-Weinberg expectations were observed. An interclass correlation test analysis was performed in order to detect any correlation between alleles at any of the pairwise comparisons of the three STR loci. The only departure from observed expectations was for the D8S1179/D12S391 comparison; the other two pairwise comparisons showed no detectable deviations. DNA samples were extracted from peripheral blood samples from 97 unrelated individuals from Rio de Janeiro's population. The considered population structure for Rio de Janeiro consists of European-derived Brazilians. African-derived and native Brazilian descendants have been excluded. This paper describes the PCR amplification, STR typing and sequencing, and statistical analysis. 8 references