Healthcare reforms and restructuring have been a global phenomenon since the early 1980s. The major structural reforms in the healthcare system in New South Wales (NSW) including the introduction and implementation of the area health management model (1986), the senior executive service (1989) and performance agreements (1990), heralded a new era in management responsibility and accountability. It is believed that the reforms, the process of the reforms, and the instability brought about by the reforms may have not only resulted in the change of senior healthcare management practices, but also in the change of competencies required for senior healthcare managers in meeting the challenges in the new era. However, limited studies have been conducted which examined how health reforms affected its senior health executive workforce and the above changes. Moreover, no study on senior healthcare managers has focused specifically on NSW after the major reforms were implemented. The purpose of this research was to examine how reforms in the NSW Health public sector affected its senior health executive workforce between 1990 and 1999 in terms of their roles and responsibilities, the competencies required, and the challenges they faced. This study, from a broad perspective, aimed to provide an overview of the NSW reforms, the forces behind the reforms and the effects the reforms may have had on senior health managers as predicted by the national and international literature. This study also explored the changes to the senior health executive workforce in the public sector during the period of rapid change in the 1990s and has provided indications of the managerial educational needs for future senior healthcare managers. Both quantitative and qualitative data have been collected by this study using triangulated methods including scientific document review and analyses, a postal questionnaire survey, and in-depth telephone interviews. The findings from the two quantitative methods informed and guided the development of the open-ended questions and overall focus of the telephone interviews. This study found differences in the characteristics and employment-related aspects between this study and previous studies in the 1980s and 1990s, and identified four major tasks, twelve key roles and seven core competencies required by senior health executives in the NSW Health public sector between 1990 and 1999. The study concludes that the demographic characteristics and the roles and responsibilities of the NSW Health senior executive workforce since the reforms of the 1980s have changed. This study also identified seven major obstacles and difficulties experienced by senior health executives and suggested that during the introduction and implementation of major healthcare reforms in NSW since 1986, barriers created by the ‘system’ prevented the achievement of its full potential benefits. Although this study did not focus on detailed strategies on how to minimise the negative impact of the health reforms on the senior health executives or maximise the chance of success in introducing new changes to the system, some suggestions are proposed. Most significantly, the study has developed a clear analytical framework for understanding the pyramidal relationships between tasks, roles and competencies and has developed and piloted a new competency assessment approach for assessing the core competencies required by senior health managers. These significant findings indicate the need for a replication of the study on an Australia-wide scale in order to extend the generalisability of the results and test the reliability and validity of the new competency assessment approach at various management levels in a range of healthcare sectors. This is the first study acknowledging the impact of the introduction of the area health management model, the senior executive service and performance agreements in the NSW public health system through an original insight into the personal experiences of the senior health executives of the reforms and examination of the major tasks that senior health executives performed and relevant essential competencies required to perform these tasks. The possible solutions identified in this study can guide the development of strategies in providing better support to senior healthcare managers when large-scale organisational changes are proposed in the future.