The aim of this study is to examine changes in the performance measurement system of a bank operating in an emerging economy during the period 1997-2007 by exploring the factors that influenced changes in its performance measurement system and its consequential responses to institutional pressures. To achieve this aim, three research questions are addressed in the thesis: i) How did the performance measurement system in a bank operating in Pakistan change over the last decade? ii) What factors influenced the changes? and iii) How did the bank respond to the factors driving change in the performance measurement system? These research questions are examined using an analytical framework informed by DiMaggio and Powell's (1983) notion of isomorphism mechanisms of institutional pressures together with Oliver's (1991) typology of strategic responses to institutional pressures. Using the case study method, data were collected from the largest state-owned bank in Pakistan (named as Pakbank in this study) for the period 1997-2007 through administering a questionnaire and conducting semi-structured interviews. Additionally, relevant internal and external documents provided a secondary data source for the study. -- The findings of the study suggest that the change in the PMS was a direct consequence of Pakbank's institutional environment. This institutional environment was significantly influenced by the bank's external environment which prior to 1997 was mainly characterised by political instability and uncertain economic conditions. These external environmental conditions led to changes in Pakbank's regulatory environment, forcing managers at Pakbank to make changes to its PMS. -- In line with DiMaggio and Powell's (1983) notion of isomorphism mechanisms of institutional pressures, the study found that the changes were forced to occur as the result of coercive, mimetic and normative pressures placed on the bank. In line with Oliver's (1991) typology of strategic responses to institutional pressures, the study found that Pakbank responded to the institutional pressures in two ways. While in the initial period of the reforms most of the impetus to change originated as formal directives from the regulators the bank passively complied with the coercive pressures to gain legitimacy. As the performance of the banking sector gradually improved and reforms proceeded, the bank increasingly applied strategic choice to the pressures with the aim to improve efficiency, performance and accountability. -- The study also found that over the period 1997-2007, the bank intensified the use of financial measures which is contradictory to the literature on manufacturing organisations within developed countries, where there is a great focus on using a combination of financial and non-financial measures. Since Pakbank wanted to improve its financial performance while complying with the new regulatory requirements, which required using extensive use of financial measures, the bank emphasised financial measures alone. -- The findings also suggest that the change in Pakbank's PMS was planned and rationally executed due to its top-down initiation. The new top management, in particular the new President, as a change agent, played a significant role in the change within Pakbank. The knowledge and experience as well as the commitment of the new President not only helped give the bank's new PMS its particular character but also played a major role in creating a culture of performance measurement and accountability. The resistance by organisational members to the changes introduced in the PMS was minimal. There was however some dissatisfaction amongst employees towards the change, as to its exact nature and its likely impact on staff. Poor communication of the PMS changes, the low level of IT support provided and limited training were the causes of such dissatisfaction. Nevertheless, the study found that the changes introduced to the PMS became institutionalised in the bank during the period under investigation. Employees used the PMS to report and measure performance of their business units and in discussions with various business units, the Management Committee and the Board. -- This study contributes to the performance measurement literature, the banking literature and the literature on emerging economies by adding to knowledge about changes in performance measurement systems in a bank in the context of an emerging economy. The insights provided in this study can assist practitioners in addressing issues concerning performance measurement systems changes in similar contexts.