Main Gate Guards (P2U) in Correctional Institutions (Lapas) hold a strategic position as the frontline in maintaining security and order within the correctional environment. This study aims to analyze the role and effectiveness of P2U duties at Class 1 Madiun Prison in enforcing security protocols, with reference to Law Number 12 of 1995 concerning Corrections. This study uses a normative juridical method with a statutory regulatory approach and secondary data from relevant literature. The results indicate that P2U has an important responsibility in inspecting and supervising people, goods, and vehicles entering and leaving the prison, and plays a role in preventing the smuggling of prohibited goods and attempts by inmates to escape. However, in its implementation, P2U still faces various obstacles such as limited human resources, lack of training and supporting equipment, and less than optimal implementation of standard operating procedures (SOPs). Therefore, an optimization strategy is needed through improving officer competence, adding security technology facilities, and developing more detailed and applicable SOPs. This research is expected to contribute to strengthening the correctional security system in Indonesia.