<![CDATA[Human Immunodeficiency Virus (HIV) remains a major public health concern, particularly among key populations at substantial risk of infection. Pre-Exposure Prophylaxis (PrEP) has been recognized as an effective biomedical intervention for preventing HIV transmission and is recommended by the World Health Organization (WHO) as part of comprehensive HIV prevention strategies. However, the integration of PrEP into primary healthcare services in Indonesia remains limited due to various implementation challenges. This study aimed to analyze the opportunities and challenges of integrating PrEP into primary healthcare services for key populations in Indonesia using the Reach, Effectiveness, Adoption, Implementation, and Maintenance (RE-AIM) framework. This study employed a narrative review design. Literature published between 2019 and 2025 was identified through PubMed, Scopus, ScienceDirect, Google Scholar, WHO reports, UNAIDS reports, and Indonesian policy documents. Eligible publications were selected according to predefined inclusion criteria and synthesized thematically based on the five dimensions of the RE-AIM framework. The implementation of PrEP is influenced by individual, organizational, and health system factors. Major barriers include HIV-related stigma, limited awareness among key populations, inadequate healthcare workforce capacity, fragmented service integration, and sustainability concerns. Conversely, policy support, community engagement, healthcare workforce development, and integration into primary healthcare services provide important opportunities to strengthen PrEP implementation. Integrating PrEP into primary healthcare services has considerable potential to strengthen HIV prevention efforts in Indonesia. Improving service accessibility, organizational readiness, workforce capacity, monitoring systems, and sustainable financing mechanisms is essential for optimizing long-term PrEP implementation.]]>
