This quantitative study examined whether Program M, an intervention targeting young women in a low-income community in the city of Rio de Janeiro, Brazil, promoted changes in gender equitable attitudes and self-efficacy in interpersonal relationships among program participants. Further, it investigated whether the program influenced these young women's behaviors, including the use of drugs, community engagement, condom use, sexual activity, and tolerance of violence. To assess the program's effectiveness, a pre- and posttest quasi-experimental design was used. During pretest and posttest, 114 women in the program group and 159 women in the comparison group, all between the ages 14-24, responded to a Health Risk Behavior Questionnaire, the Self-Efficacy in Interpersonal Relationships Index (SEMI), and the Gender Equity Scale for Women (GESW). Regression analyses were used to test two hypotheses, namely 1) that Program M has an effect on young women's levels of self-efficacy, gender equity and self-reported behavior change, and 2) that program effect differs by income, age, and education level of participants. The results indicated that program M indeed had an effect on self-reported self-efficacy in interpersonal relationships, sexual activity, and drug use. In addition, the results suggested that Program M's effect on women's self-reported self-efficacy in interpersonal relationships varied by level of education. Program effects were greater for the least educated women, decreased with higher levels of education, and were not present among the best-educated women with roughly 10 or more years of education. The program's effect on self-reported sexual activity differed by age. Older women in the program were more likely to report increased sexual activity compared to younger women. Further, the results suggest that the program may have decreased the probability of higher sexual activity among girls younger than 17 years of age. Program participation was also associated with decreased self-reported drug use. Finally, the program did not have an effect on women's self-reported levels of gender equity, tolerance of domestic violence, and community participation, even though those topics were included in the program's activities. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.]