en عمومى General پژوهشي Original article Background and Aims: Genotyping assay has been accepted as a guidance in the therapeutic management of Human Immunodeficiency virus 1 (HIV-1). But, it is not commonly used in our country due to its high running cost. The aim of this study is evaluate an in-house genotyping resistance test (GRT) for HIV-1. Methods: HIV-1 RNA of 20 samples were extracted from plasma and RT Nested- PCR was performed and the final products were sequenced. Stanford HIV Sequence Database was used for genotyping and interpretation of resistance data. Results: Subtype A was the dominant viral subtype in these patients. Also the results of drug resistance interpretation showed that drug-naïve patients are susceptible to drugs and for patients taking the drugs 66.6% susceptible for AZT, 50% high- level resistance for 3TC, 66.6% low- level resistance for ABC, 66.6% susceptible for TDF, 50% high- level resistance for NVP and 50% high- level resistance for EFV. Conclusion: Our method is able to amplify and sequence HIV-RNA from plasma samples from a random selection of patients encompassing different subtypes. The results of this study may have important consequences for survey and clinical management of patients with AIDS in Iran. Human Immunodeficiency Virus Type 1, Subtypes, Genotyping, Drug Resistance 7 11 http://journal.isv.org.ir/browse.php?a_code=A-10-1-49&slc_lang=en&sid=1 K Baesi 10031947532846003716 10031947532846003716 No Research Center of Virus and Vaccine, Baqiatallah University of Medical Sciences, Tehran, Iran E Saberfar 10031947532846003717 10031947532846003717 Yes Research Center of Virus and Vaccine, Baqiatallah University of Medical Sciences, Tehran, Iran M Haji-Abdolbaghi 10031947532846003718 10031947532846003718 No Iranian Research Center for HIV/AIDS (IRCHA), Imam Khomeini Hospital, Tehran University of Medical Sciences, Tehran, Iran Z Goodarzi 10031947532846003719 10031947532846003719 No Research Center of Virus and Vaccine, Baqiatallah University of Medical Sciences, Tehran, Iran