Young migrant workers working in the industrial zones (IZ) in low and middle-income countries are at risk for HIV and other sexually transmitted diseases. This study examines the sex-related risks of young women migrant workers in the IZ in Vietnam. This cross-sectional survey was conducted among 1,061 young migrant women working in the IZ park in Hanoi, Vietnam. Multivariate logistic regression analysis was used to identify factors associated with HIV testing and condom use at last sex. A total of 1,061 young women migrant workers completed the survey in which 652 participants consented to take the initial rapid HIV test. All but one participant tested negative indicating a HIV prevalence of 150 (95% CI: 27-860) per 100,000 population among this population. There were no differences in sexual behavior, use of sexual and reproductive health services, HIV knowledge, perceived HIV risk or alcohol use between those who were HIV tested and those not tested. Single participants reported high rates of first sex while living in the IZ and high rates of condom use during the first-time sex, however, they had low levels of condom use at last sex. While the majority of married participants used the SRH/HIV services, nearly 80% of the single participants who reported having sex never used SRH/HIV services since living in the IZ. However, single participants were over 4 times more likely to use condoms at last sex compared to married participants (OR = 4.67; 95%CI = 2.96-7.85). Participants with vocational school or higher education was more likely to use condom (OR = 2.19; 95%CI = 1.05-4.57). Neither HIV knowledge or alcohol use were associated with condom use. Although HIV prevalence is very low among young women workers in the IZ in Vietnam, a significant number of them engaged in risky sexual behavior and low levels of condom use at last sex as well as low level of using SRH/HIV services highlights a need to develop interventions that provide tailored-made and cultural appropriate SRH education for unmarried female migrant workers to prevent risky sexual behaviors, sexually transmitted diseases and unwanted pregnancy.