BACKGROUND: Despite the relatively low prevalence of HIV/AIDS in Korea, the incidence of HIV is steadily increasing, centering on same-sex sexual contact among men in their 20s and 30s. However, in Korean society, where acceptance of homosexuality is low, LGBTQ + research is lacking and there is little empirical data on HIV transmission. This study explored the context in which anal intercourse occurs among male sexual minorities in Korea. METHODS: Data were collected by conducting a web survey targeting paid members of Korea's largest homosexuality portal site (n = 941). The dependent variable was whether anal intercourse was preferred, and the major independent variables were health behavior, health status, and sexual behavioral characteristics. RESULTS: Those who reported that their gender identity was homosexual tended to prefer anal sex more than those who reported that they were bisexual (Chi-square = 5.165, p <
.05). For homosexuals that had more unprotected sex (OR = 1.538, 95% CI = 1.281-1.847), had a primary sex partner (OR = 1.943, 95% CI = 1.345-2.809), and had been diagnosed with an STD (OR = 2.978, 95% CI = 1.592-5.568), there was a high possibility of preferring anal intercourse. Bisexuals were more likely to prefer anal intercourse if they had unprotected sex (OR = 1.715, 95% CI = 1.322-2.225) or had a primary sex partner (OR = 1.927, 95% CI = 1.141-3.257). CONCLUSIONS: This study found that young non-heterosexual men in South Korea are more likely to engage in condomless anal sex while living with HIV/STDs. As a result, primary partners are at higher risk of infection, and bisexual individuals are more likely to transmit HIV/STDs due to similar sexual contexts.