The aim of this communication was to describe the detection of the coexistence of HIV-1 variant with dipeptide insertion between codons 69 and 70 of reverse transcriptase. These variants were isolated from a 16-year-old male patient, undergoing treatment in the city of Marilia, SP, Southeastern Brazil. After confi rmation of treatment failure, resistance to antiretroviral drugs testing was performed and two variants with the insertions of the aminoacids Ser-Gly/ Ser-Ala at codon 69 of reverse transcriptase were detected, besides the T69S mutation. These insertions have low prevalence, have not been reported in situations of coexistence in Brazil and are related to multidrug resistance, which makes this epidemiological fi nding relevant.