For today's rapidly changing business environment are characteristic changes like globalization of the market place, technological changes, increased business complexity, intensified global competition, increased customer bargaining power, new resources of competitive advantage and more. Therefore, to be successful and able to compete in this environment, companies must identify and analyze their existing position, define mission, vision, strategic goals and operate more effectively. The key to success is to increase the effectiveness and efficiency of all business processes based on measurement and management of their performance. Using performance management system companies can plan, measure and manage the performance of all company activities. Properly designed, created and implemented performance management system can then help the company achieve the desired outputs. The literature, however, states that this is not a simple task, and many companies have problems especially with implementation of these systems. Unfortunately, it is still not quite clear what factors influence successful development, implementation, usage and continuous improvement of the performance management system in companies. There is a gap in the identification of factors influencing the development, implementation, usage and continuous improvement of the performance management system, their detailed study and analysis in practice. For this reason, it is important to deal with the identification, analysis and study of internal and external factors influencing the implementation and continuous improvement of performance management system. The aim of this paper is to identify and analyze internal and external factors influencing the implementation and continuous improvement of the performance management system, which these companies use. In the questionnaire survey is particularly investigated whether managers of surveyed companies are able to identify factors influencing the implementation and continuous improvement of the performance management system. Afterwards is carried out a detailed description of selected key internal factors, and their detailed analysis including identification of the relationship of these factors to the performance management system. Data were obtained by mail questionnaire survey on a sample of large manufacturing and non-manufacturing companies operating in the Czech Republic. The research findings are evaluated within the context of the theoretical background and the conclusions of similar studies.