The present study investigated prevalence of integrase strand transfer inhibitors (INSTI) resistance mutations in HIV-1-infected antiretroviral therapy (ART)-naive patients in Korea. From 106 plasma samples, amplification and sequencing of integrase genes was performed, and major or minor mutations were calculated by the Stanford HIV drug resistance mutation interpretation algorithm. No major INSTI resistance mutations were found, and 14 minor mutations were detected in 13 (12.3%) patients. The present data support the recommendation that routine testing for INSTI resistance mutations before starting ART is not necessary.