Some believe that the educational system in Libyan schools constitutes an obstacle to development, due to the short length of the school day, which does not meet the needs of students. This prompted the Ministry of Education to propose the "full-day school" initiative, as is practiced in some countries around the world. This study aims to analyze the challenges facing the implementation of the full-day school system in Libyan schools, with a focus on rehabilitating the infrastructure of primary schools to meet the requirements of this system. The research relied on a descriptive, analytical, comparative approach to assess the capabilities of existing schools in the city of Khums as a case study and draw lessons from leading international experiences. The results revealed a structural gap between the infrastructure of existing schools and the requirements of the full-day school system, represented by a severe shortage of extracurricular facilities, insufficient basic services, and weak technological infrastructure. The study provides interim recommendations (short, medium, and long-term) for the rehabilitation and development of existing schools, drawing on successful international experiences, while emphasizing the importance of interim planning and adequate funding............... Keywords:.......... Education, full-Day School, Infrastructure, Challenges, Rehabilitation.