The study aimed at the role of physical education curriculum implementation for the development of physical fitness among secondary schools of yilmana densa woreda. The research assessed the safety, efficiency, effectiveness, and sustainability of the PE program. A purposive sampling method was employed to select 22 secondary school teachers and 10 principals, while 372 students were chosen through simple random sampling. To achieve the study’s objectives, both qualitative and quantitative data collection and analysis methods were utilized, including questionnaires, observation guides, resource checklists, and document analysis guides. Descriptive analysis techniques, such as frequencies and percentages, along with content analysis, were used to interpret the data. The study found that the implementation of the PE curriculum was largely inadequate in successfully teaching physical fitness. Many schools lacked policies, health and safety measures, risk and safety management practices, and medical preparedness, rendering the curriculum unsafe. Additionally, the curriculum was found to be inefficient, as schools were under-equipped with facilities, equipment, financial resources, and reference materials. Instructional issues were prevalent among the majority of teachers, and assessment practices were poorly structured. Although most students expressed a positive attitude towards physical activity and PE, there were significant limitations in acquiring movement skills. Furthermore, the sustainability of the secondary school PE curriculum was compromised by a lack of access to facilities, equipment, appropriate teaching spaces, funding, and administrative support. Based on these findings, the study recommends that health and safety management practices should be prioritized by school management, with proper policies in place. The provision of adequate PE learning facilities and equipment should be mandated for all secondary schools, and all stakeholders must support the implementation of the PE curriculum to ensure its sustainability. Continuous evaluation of the PE program is necessary to enhance its effectiveness. The findings of this study provide valuable insights for educational stakeholders, including policymakers and curriculum developers.