Purpose – In the study, it is aimed to determine the performance of companies producing complementary health insurance. Design/methodology/approach – In this study, insurance companies operating in Turkey between 2017 and 2021 and producing complementary health insurance were examined according to the "Gray Relational Analysis" method by using the number of personnel, total assets, equity, technical profit / loss, total income, number of insured and total premium variables. Findings – As a result of the study, it is seen that the companies producing complementary health insurance have increased in terms of the number of companies over the years and their performance has been at the same level. It has been determined that the variables used in determining the performance of the company have an effect on the performance, especially the number of insured persons and the performance of the companies that increase the premium production. Discussion – Today, as for every company, determining the level of performance within insurance companies has become an important issue. The level of performance should be determined in order to make a profit, to insure more insured people, to compete with competing companies. While this research is expected to provide information and equipment for the insured and insurance companies, it is also expected to contribute to the researchers who want to work in this field in terms of literature.