CCR2 is a member of the superfamily of seven transmembrane domain G protein-coupled receptors, the largest receptor superfamily in the human genome. CCR2 acts as a receptor for MCP-1 (CC chemokine) and as a co-receptor for HIV-1 cell-target entry. The gene encoding this receptor is mapped to the chromosome band 3p21. A G-to-A transition at position 190 characterizes the CCR2-64I mutation, causing valine to isoleucine substitution in codon 64. This mutation has been identified as an important factor for delaying progression to AIDS. Here, we determined the prevalence of this allele in three different Brazilian populations: 261 Amerindians inhabiting an isolated region in northern Brazil (82 samples from the Waiampi tribe, and 179 samples from the Tiriyó tribe); 89 German descendents from Joinville, a city in southern Brazil; and 305 individuals of predominantly African ancestry, from Salvador, a city in northeast Brazil. The CCR2-64I mutant allele was identified in 26% of the Tiryió and 30% of Waiampi samples, in 18% of the Joinville samples, and in 14% of the Salvador samples.