Security in jail dormitories is a critical component of correctional administration, directly affecting the safety of persons deprived of liberty (PDLs), jail personnel, and the surrounding community. In the Philippine context, particularly within the National Capital Region (NCR), male jail dormitories face persistent challenges arising from overcrowding, limited infrastructure, manpower constraints, and evolving security threats. This dissertation assessed the implementation and effectiveness of security measures in male jail dormitories in the NCR and identified opportunities for enhancement aligned with both national policies and international correctional standards. An explanatory sequential mixed-methods research design was employed. The quantitative phase utilized structured survey questionnaires administered to jail personnel and persons deprived of liberty to determine the level of implementation and effectiveness of security measures across six dimensions: physical security, procedural security, dynamic security, personnel competency, technology and surveillance, and compliance with Bureau of Jail Management and Penology (BJMP) standards. Inferential statistical tools were used to examine significant differences in perceptions between staff and PDLs and to analyze relationships between implementation and effectiveness. The qualitative phase involved key informant interviews with selected jail administrators, frontline officers, and PDL representatives to provide deeper contextual understanding of the quantitative findings. Results revealed that while security measures were generally implemented and perceived as effective, notable gaps persist, particularly in technology deployment, manpower adequacy, and consistency of procedural enforcement. Differences in perception between jail staff and PDLs highlighted areas of misalignment that may undermine dynamic security and institutional trust. Qualitative findings further emphasized overcrowding, aging facilities, and limited training opportunities as structural barriers to optimal security performance. Based on these findings, the study proposes a comprehensive security enhancement framework that integrates infrastructural improvements, personnel capacity-building, procedural refinement, and technology-driven solutions. The study contributes to criminological scholarship and provides evidence-based recommendations to strengthen jail security management while upholding human rights and rehabilitative goals. Keywords: Jail Security, Male Dormitories, BJMP, Mixed Methods, Correctional Management, National Capital Region