At what stage of reform in the public sector does it become possible to conduct a through appraisal of results and how does one know when this stage has been reached? How should such an assessment be undertaken? By what methods can comprehensive and far-reaching systemic reforms be evaluated in the arena of public management during recent decades, particularly in countries like Australia, Britain and New Zealand? Most assessments have focused upon specific changes in management practice including the introduction of performance pay, the move to accrual accounting, the growth of contracting-out, the separation of policy and operations of the devolution of human resource management responsibilities. Alternatively, they have dealth with management changes in particular policy domains - such as health care, education, community services or criminal justice - or within a particular organization (department, agency or private provider). By constrast, there have been relatively few macro evaluations - comprehensive assessments of the impact of root-and-branch changes to the system. The problems of evaluation in the arena of public management are inherently complex and the way ahead is by no means clear. This article offers offers some broaed reflections on the limitations to policy evaluation in the field of public management, and more particularly explores the obstacles confronted when assessing the consequences of systemic management reforms. It focuses on recent changes in the New Zealand public sector to illustrate the general themes because these reforms constitute one of best examples of systemic changes anywhere in the world