This article reports on predictors of condom use with casual female sex partners on the part of Latino migrant day laborers in the San Francisco Bay Area. Results come from a secondary analysis of data from a cross-sectional survey using convenience sampling to interview 290 sexually active adult, male, migrant Latino day laborers. Regression analysis of sociodemographic background, behavioral, and psychosocial predictor factors revealed a number of significant findings. Men with wives or partners currently living in Mexico were almost 4.5 times more likely to use condoms with casual female sex partners compared to men accompanied by wives or partners in California. It was also found that men at high sexual risk for HIV with casual female partners were more than 5.5 times more likely to use condoms than men at low risk. Interpretations of findings and implications for HIV prevention with this unique and especially marginalized population of Latinos are discussed. (Contains 2 tables.)