Rapid socioeconomic transformation in Vietnam in last 15 years has been followed by more liberation of sexual expression and representation of sexual identity among young people. There has been an increase in the visibility of homosexual men in major cities of Vietnam who were largely an unknown population until the emergence of the HIV epidemic. Men who have sex with men (MSM) are now considered as one of the target groups in many HIV prevention programs. This qualitative study examines local identities, relationships, and sexual practices among young MSM aged 15-24 in the cities of Hanoi and Ho Chi Minh City. Our analyses were based on 26 in-depth interviews and 10 focus group discussions with young MSM recruited through public place intercepts and cruising areas. Data document the linguistic classification, sexual relationships and behaviors, identity and process of homosexual identification, and the potential linkage between sexual identity and sexual behaviors of MSM in Vietnam. Data also highlight the stages of homosexual community development in urban Vietnam and important differences between Vietnam and the West in the representation of homosexual identity, relationships, and practices. In light of the findings, we suggest that the continuing development and elaboration of a homosexual community in Hanoi and Ho Chi Minh City offers significant opportunities for targeted HIV/AIDS prevention activities in the Vietnamese MSM population.