Associations among mother-daughter attachment, mother and daughter substance abuse, and daughter's sexual behavior under the influence of drugs and alcohol were investigated among 158 adult U.S. Latina daughters. Latina daughters were sampled from four mother-daughter dyad types: substance abusing mother and daughter, substance abusing mother only, substance abusing daughter only, and non-substance-abusing mother and daughter. Substance abusing daughters with substance abusing mothers, and daughters who were less strongly attached to their mothers, reported more sex under the influence of drugs. Age, marital status, substance abuse, and mother's substance abuse all influenced the daughter's sex under the influence of alcohol. An unexpected positive association between attachment and sex under the influence of alcohol was found for daughters who were more closely attached to a substance abusing mother. Implications for future research, and HIV/AIDS and drug prevention and treatment programs for Latinas are discussed.