Chaos and complexity theories are born from a non-linear science approach. In Chaos theorem, it is clear that everything that really is related to each other and that these relations are constantly changing, small things can have great consequences by creating a domino effect. Because human beings can not have the analysis method for these systems, the predictions about the systems can give incorrect results. Chaos arises at this point. Another concept closely related to chaos is the complexity involving the operation of systems with nonlinear dynamics and developmental characteristics. The critical point of the complex systems approach is the macroscopic view of the development of political, social, or cultural arrangements. Health care has some features that make science of complexity a useful tool. These fetures are, information asymmetry between service provider and service area,technological and professional heterogeneity at a significant level, current administrative and political issues are the result of the past of health care in the cultural environment. The aim of this study is to evaluate the theories of health services by explaining theories of chaos and complexity and complex adaptive systems. As a result of the study, it is seen that, in the literature, studies that study chaos and complexity theories in health services are theoretical studies to explain in which aspects the health institutions have the characteristics of science of complexity.