The impact of a professionally facilitated peer group intervention for HIV prevention among 400 low-income Chilean women was examined using a quasiexperimental design. At 3 months postintervention, the intervention group had higher HIV-related knowledge, more positive attitudes toward people living with HIV, fewer perceived condom use barriers, greater self- efficacy, higher HIV reduction behavioral intentions, more communication with partners about safer sex, and decreased depression symptoms. They did not, however, have increased condom use or self-esteem. More attention to gender barriers is needed. This intervention offers a model for reducing HIV for women in Chile and other Latin American countries.