This study was designed to develop the scale of the Complex Adaptive Leadership for School Principals (CAL-SP) and examine its psychometric properties. This was an exploratory mixed method research design (ES-MMD). Both qualitative and quantitative methods were used to develop and assess psychometric properties of the questionnaire. This study introduced the construct of CAL-SP, which comprised three dimensions: enabling leadership (EL), managerial leadership (ML) and adaptive leadership (AL). The scale showed internal consistency, reliability, construct validity and nomological validity explaining that the instrument had a good structure and reliability. Directions for future research and managerial implications of the new construct are discussed.