Research goal: The goal of this research is to investigate the impact of obesity on treatment of anemia in patients undergoing hemodialysis. Study outline: cross-sectional study Subjects and methods: The research included 121 patient undergoing hemodialysis treatment at the Department of Nephrology of the University Hospital Center Osijek. Data was collected about treatment of anemia and the average doses of erythropoiesis-stimulating agents (ESA) and iron during six months of treatment. The patients were divided into two groups: obese patients, whose body mass index (BMI) ≥ 30 kg/m2, and non-obese patients, whose BMI < 30 kg/m2. Results: The prevalence of dialysis-treated patients (HD patients) is 27.3%. No statistically significant difference was found regarding causes of chronic kidney disease (CKD) between obese and non-obese patients. No statistically significant difference was found in weekly ESA doses received by obese and non-obese patients. No statistically significant difference was found in anemia treatment adequacy between obese and non-obese patients. There was an observed trend of reduction of ESA doses (IU/kg/weekly) and values of the erythropoietin resistance index in BMI subgroups for first, second, and third levels of obesity (p=0,02). Conclusion: The incidence of obesity in HD patients conforms to the incidence in general population. The most common diseases that lead to CKD in obese and non-obese patients are arterial hypertension and diabetes. Obese and non-obese patients receive the same weekly ESA doses. Adequate anemia treatment that entails adequate iron levels and achieving target hemoglobin levels is received by obese and non-obese patients, without a statistically significant difference.