Though AIDS case rates among Asian Pacific Islander Americans (APIs) in the United States remain relatively low, the number has been steadily increasing. Scholars, policy makers, and service providers still know little about how confident APIs are in carrying out different HIV risk reduction strategies. This article addresses this gap by presenting an analysis of a survey of API women and youth in Orange County, California (N = 313), a suburban county in southern California with large concentrations of Asian residents. Multivariate logistic regression models using subsamples of API women and API youth respondents were used. Variations in reported self-efficacy for female respondents were explained by acculturation, comfort in asking medical practitioners about HIV/AIDS, and to a lesser degree, education, household size, whether respondents were currently dating, HIV knowledge, and whether respondents believed that HIV could be identified by physical appearance. For respondents younger than 25 years, variations in self-efficacy were related to gender, age, acculturation, HIV knowledge, taking-over-the-counter medicines for illness, whether respondents were dating, and to a lesser degree, employment, recent serious illness, whether they believe that one could identify HIV by how one looks, and believing that illness was caused by germs. Implications for HIV prevention programs and future research are provided.