Traditional Vietnamese culture places women in a subordinate position, rendering them disadvantaged in the negotiation of sexual and contraceptive decisionmaking. Drawing on data from 4,632 married women surveyed in the 2005 Vietnam Population and AIDS Indicator Survey, this study examines the relationship between women's sociodemographic characteristics, their self-efficacy in negotiating sexual activity and condom use, and their consistency and recency of condom use. Results from our structural equation models indicate that women's self-efficacy is significantly correlated with both condom use at last sex and consistent condom use in the past 12 months. Knowledge that condom use can prevent HIV also strongly predicts consistent use. Having a son is related to women's self-efficacy but not to condom use outcomes. This study suggests that the availability of condoms for disease prevention should continue to be widely promoted, and that efforts should be made to assist women in asserting their need for protection from HIV infection.