Diabetes mellitus is a metabolic disease, which is getting more and more attention every year. But despite this, the number of cases continues to increase rapidly, and the number of people with direct risk factors for this disease — obesity, physical inactivity and dysmetabolic disorders — is also growing. In addition to the fact that diabetes mellitus and its complications reduce the quality of life of the population and are disabling, they also require quite significant economic costs, which is not so often covered. In our article, we analyzed the medical documentation of inpatient patients, and as a result presented data on the economic costs of patients depending on the type, length of service and the presence or absence of complications of diabetes mellitus.