The Committee to Protect Journalists (CPJ) is one of many nonprofit, nongovernmental organizations that work to defend press freedom and the safety of journalists in Latin America. Based on qualitative interviews with employees at the CPJ, open surveys with journalists who have been helped by the CPJ, historical archive research, and informal participant observation, this study shows that organized domestic and international nongovernmental groups can and do make improvements on behalf of journalists and press freedom in Latin America. The CPJ's activities raise issues and place them on the agenda, and they influence discourse, policy, institutional procedures, and state behavior. Effectiveness at these levels is conditioned upon the involvement of local press groups, target audiences, the issues addressed, the credibility and authority of the CPJ, and the organization's connections within the worldwide press freedom network. This case study helps fill a significant gap in the research on transnational advocacy and its influence, and provides a foundation upon which to further explore the roles of advocacy networks in the international community.