Latinas in the United States are more likely to be diagnosed with late-stage breast cancer (BC) compared to non-Latinas. Literacy-appropriate and culturally sensitive cancer communication interventions can help address existing racial/ethnic BC disparities. We formatively developed a new BC prevention brochure for Spanish-speaking Latinas ([greater than or equal to] 35 years). Eligible women (n = 240) from a large public hospital in California were randomly assigned to one of three study arms: Group 1 received the new brochure, Group 2 included a community health worker (CHW) who delivered the new brochure's content, and a control group received a standard educational brochure. Participants completed three surveys (baseline, postintervention, 3-month follow-up) with a 100% completion rate for the first two surveys and 80.4% completion after 3 months. We assessed the difference in outcomes for BC risk knowledge, perceived BC susceptibility, and BC information self-efficacy between groups. Participant mean age was 52.3 years, and 82.1% reported low English proficiency. Mean knowledge scores increased and perceived BC susceptibility improved for all groups (p [less than or equal to] 0.05), yet treatment effects were not significant between groups for these outcomes. BC information self-efficacy also increased from baseline to postintervention for all groups to >80%. After 3 months, only Group 2 and the control group retained their increases and treatment effects were significant only for Group 2 compared to other groups in unadjusted and adjusted models. A CHW-delivered intervention may be more effective in improving BC information self-efficacy among Latinas compared to print material alone. More research is needed to examine the efficacy of CHW-delivered interventions.