The paper aims to investigate the intricate relationship between accounting information systems, managerialism and accountability in Local Governments. The exploratory case study was conducted using a mix of method both qualitative and quantitative, in the context of a medium-size Italian municipality. The findings confirm that the quality of accounting information systems is central in the managerial development of an organisation, public but also private, and the presence of internally coherent systems of accountability. The technological and procedural slack of the AIS allows managers to develop their private information systems to fulfil also accountability obligations or needs. The uncontrolled introduction of the reforms brought about the development of conflicting forms of accountability, the search for internal and external legitimation by managers, to protect themselves from the political influence and the attempt to evaluate their performance. The paper provides interesting insights on the impact of accounting/managerial based public sector reforms on the inner functioning of Local Government, emphasising the risk of delivering changes not foreseen by the official aims.