This study analyses principals’ managerial competencies for effective management of school resources in secondary schools in Anambra State. The study was conducted in Anambra State. The study population comprised 257 principals in public secondary schools in the State. The study adopted a descriptive survey design. A 24 items researcher developed instrument titled “Principals’ Managerial Competencies for Effective Management of School Resources Questionnaire (PMCEMSRQ)” was used for data collection. The Cronbach alpha was used to determine the reliability of the instrument which yielded a high reliability coefficient of 0.85. The study found out that secondary school principals’ in Anambra State do not have managerial competencies in procurement of physical and instructional materials, provision of e-library facilities and equipping classrooms and offices with needed furniture for effective material resource management. The study also found out that school principals’ have managerial competencies in prioritizing financial allocation according to school needs, keeping accurate financial information of the school, ensuring accountability in all school expenditures, carrying out periodic auditing of school budgets and adopting cost-saving strategies for effective financial resource management among others. The study recommended that School principals’ should strive to acquire managerial competencies in involving teachers’ in decision making, organizing seminars and workshops for professional advancement of teachers, providing incentives’ for students’ for effective human resource management in schools, procurement of physical and instructional materials, provision of e-library facilities and equipping classrooms and offices with needed furniture and other school materials for effective material resource.