The study explored challenges faced by school leaders in the Pacific nation of Solomon Islands in school-based assessment, and the adequacy of an assessment course to prepare them. A questionnaire including both open and closed-ended questions elicited relevant data from the school leaders. Modelling best practices in school-based assessment was recognised as a major challenge for them. Their responses indicate their feeling that the limitations of their knowledge and skills lie at the heart of their difficulties in effective use of this assessment method. They trace the origin of their problems to an initial teacher training programme that included little on assessment, which adversely affected their ability to work as instructional leaders in assessment for learning and teaching in schools. Their critical reflection on the assessment course they completed as part of a current leadership programme suggests the preparation has been adequate in giving them new knowledge and skills in applying best practices in school-based assessment. Though only on a small scale, this study implies that greater attention to this area to promote children's learning is warranted. The value of best practices in assessment is applicable not only in Solomon Islands but also in other education systems within and beyond the Pacific region, to ensure meaningful progress and development in education.