['Information is limited about HIV-1 subtypes circulating in less populated Brazilian areas where the AIDS epidemic is expanding, such as in the Central West region.', 'To describe HIV-1 subtypes in patients from the States of Goias, Mato Grosso do Sul and Mato Grosso in Central West Brazil.', 'Heteroduplex mobility analysis of nested-PCR products from env (primers: ED5/ED12, ES7/ES8) and gag regions (primers: H1P202/H1G777, H1Gag1584/g17) of 406 HIV-1 isolates from Goias (n=271), Mato Grosso do Sul (n=85) and Mato Grosso (n=50) collected from 2001 to 2004.', 'Median age of patients was 26 years (1-79 range), 68.7% (279/406) females, 69.9% (269/385) sexual exposure, 14.3% parenteral risk, 15.8% vertical cases. Overall 69.9% (284/406) of HIV-1 subtypes were concordant B(env)/B(gag), 1.7% F(env)/F(gag) and 1% C(env)/C(gag). Discordant HIV-1 isolates were 14.5% (59/406), mainly B(env)/F(gag) and F(env)/B(gag) (49/59); five were B(env)/D(gag), four B(env)/C(gag) and one C(env)/D(gag). B/B and discordant B/F isolates were detected among all risk categories and among children and adults.'] Does molecular screening show extensive HIV-1 genetic diversity in Central West Brazil?