Although most secondary schools do use management information systems (MISs), these systems tend not to be used to support higher order managerial activities but are currently primarily used for clerical purposes. This situation is unsatisfactory as MISs fully utilised could offer invaluable support to schools, which are increasingly being granted autonomy in the development of school policy. This study investigated whether training school principals thoroughly could improve the utilisation of MISs in schools. The results demonstrate the positive effects of a deliberately designed training course on school principals' knowledge of MISs, attitudes towards MISs, and skills required to effectively use MISs to support decision-making.[Copyright of School Effectiveness and School Improvement is the property of Routledge. Full article may be available at the publisher's website: http://dx.doi.org/10.1080/09243450701712577]