The goal of this study is to determine the etiology, nature, concomitants and consequences of drug abuse by homeless women with a history of recent drug use, and seek a scientific basis for decision-making regarding drug use and risky sexual behavior in these women. Women residing in randomly selected homeless shelters (HSs), stratified proportionately by ethnic groupings consisting of African-American, Latina or White women, will be invited to participate in the study. A quantitative assessment will be conducted with 1400 (900 recent drug- dependent and 500 non-drug-dependent) homeless women by nurses and outreach workers of the subjects' ethnicity. The non-drug-dependent women will serve as a theoretical sample to identify variations in the phenomena under investigation. Hair analysis will be conducted to verify drug use status. Variables to be assessed include: a) Situational factors (concerns, history of parental dysfunction, abuse as a child, and parental or guardian drug use); b) Personal factors (self-esteem); c) Social factors (social support); d) Cognitive Appraisal factors (perceived seriousness of drug dependency, rewards and costs of drug dependency, perceived self-efficacy in drug abstinence and condom use); e) Cultural factors; f) Sociodemographic factors; g) Health Seeking and Coping Responses, which include drug use and risky sexual behaviors, or health protecting behaviors; and h) Health Outcome, as measured by physical health, emotional distress, STDs, and unwanted pregnancies. Structural equation modeling of a revised theoretical framework will be conducted to assess its ability to predict decision-making regarding drug use and risky sexual behaviors, as well as health protecting behaviors and health outcome of the women studied. An indepth qualitative assessment will also be conducted with a randomly selected subsample of 300 drug-dependent women stratified proportionately by ethnicity by means of a semi- structured interview guide administered by the research staff. Specific aims of the qualitative research are to describe: l) the decision-making processes of homeless women in initiating drug use; 2) their pattern of drug use over time; 3) factors that influence initiation into and continuation of drug use; 4) factors that motivate or prevent women from entering drug treatment; and 5) the impact of drug dependency on health outcome. The longterm goals of the study are to contribute to knowledge about drug dependency among homeless women in order that population and ethnic-specific intervention and prevention strategies can be developed.