This study reviews initiatives that aim to prevent child sexual abuse material (CSAM) offending, including evidence of effectiveness. Information was sourced via a literature search and input from an international expert advisory group. The study identified 74 initiatives in 16 countries, and 34 eligible studies measuring implementation and effectiveness. The CSAM offending prevention initiatives identified in the study include helplines, therapeutic treatment and psychoeducation, online self-management courses, education and awareness campaigns, and other forms of support. Importantly, findings indicate that media and social media campaigns have successfully reached large numbers of offenders, both detected and undetected. While outcomes of programs are mixed, findings indicate that prevention initiatives can encourage help-seeking, reduce risk factors for offending, enhance protective factors, and reduce contact sexual offending against children. Findings also suggest that initiatives aimed at contact child sexual abuse offenders are not necessarily effective in reducing CSAM offending. Evaluations of initiatives aimed specifically at CSAM offending show promise but are limited methodologically. Further and more robust evaluations are required to determine their effect on CSAM use.