Performance measurement makes up the core of all health care systems in transition. Many countries and institutions monitor different aspects of health care delivery systems for differing purposes. Health care deliverers are compared, rated, and given incentives with respect to their measured performance. However, a global health care domain is currently striving for attaining commonly accepted performance measurement models and base-standards that can be used in information systems. The objective of this thesis is to develop an ontological framework to represent performance measurement and apply this framework to interpret performance measurement studies semantically. More specifically, this study made use of a formal ontology development methodology by utilizing web ontology and semantic web rule languages with description logic in order to develop a commonly accepted health care performance measurement ontology and knowledge base system. In the ontology developed, dimensions, classes, attributes, rules and relationships used in health care delivery and performance measurement domain are defined while forming an initial knowledge base for performance measurement studies and indicators. Furthermore, we applied the developed performance measurement ontology to the knowledge base while driving those related performance indicators for predefined categories. The ontology is evaluated within the features of the Turkish health care system. Health care deliverer categories are identified and by executing inference rules on the knowledge base, related indicators are retrieved. Results are evaluated by domain experts coming from regulatory and care provider institutions. The major benefit of the developed ontology is that it presents a sharable and extensible knowledge base that can be used in the newly emerging performance measurement domain. Moreover, this conceptualization and knowledge base system serve as a semantic indicator search tool that can be used in different health care settings.