Since the second half of the twentieth century, there have been significant changes in the science of finance with the models and theories introduced to the literature, and the foundations of modern finance have been laid. Numerical handling of concepts such as risk, expected return, portfolio; It has been a guide for individuals, institutions and states. It has emerged that the units that supply and demand funds in the financial system should act optimally in their investment decisions. The concept of risk is a concept that affects all units and has a volatile effect on portfolios. The risk, which is defined as the realization of possible negative situations, can be managed with various strategies and can be prevented by taking precautions. Although there are many types of risk, there are types with preventable and non-preventable structures. Banks are institutions that are important among financial institutions and are exposed to many risks due to their structure. In order to ensure effective risk management and create a standard structure in the banking system, Basel agreements were made and important decisions were taken. It is important for all units that the system, which has many functions in the financial system, has a sustainable structure and is financially successful. In the study, it is aimed to define the concept of risk in the banking system with its types and to evaluate it with the Basel process. Capital adequacy, which is an important output of the Basel process, has been evaluated and the capital adequacy ratios of banks operating in the Turkish banking system have been examined. By making a general evaluation; Inferences have been made about the structure of banks, the types of risks they are exposed to and their capital adequacy.