Introduction Studies have shown that iron metabolism is affected by coronavirus disease 19 (COVID‐19), which has spread worldwide and has become a global health problem. Our study aimed to evaluate the relationship between COVID‐19 and serum erythropoietin (EPO), hepcidin, and haptoglobin (Hpt) levels with disease severity, and other biochemical values. Methods Fifty nine COVID‐19 patients hospitalized in the intensive care unit (ICU) and wards in our hospital between March and June 2020 and 19 healthy volunteers were included in the study. Participants were divided into mild, severe, and critical disease severity groups. Group mean values were analyzed with SPSS according to disease severity, mortality, and intubation status. Results Hemoglobin (Hb) levels were significantly lower in the critical patient group ( P < .0001) and deceased group ( P < .0001). The red blood cell distribution width‐coefficient of variation (RDW‐CV) and ferritin values were significantly higher in the intubated ( P = .001, P = .005) and deceased ( P = .014, P = .003) groups. Ferritin values were positively correlated with disease severity ( P < .0001). Serum iron levels were lower in the patient group compared with the reference range. ( P < .0001). It was found that the transferrin saturation (TfSat) was lower in the patient group compared with the control group ( P < .0001). It was found that the mean EPO of the deceased was lower than the control group and the survived patient group ( P = .035). Hepcidin levels were found to be significantly lower in the patient group ( P < .0001). Hpt values were found to be significantly lower in the intubated group ( P = .004) and the deceased group ( P = .042). Conclusion In our study, while serum iron and hepcidin levels decreased in patients diagnosed with COVID‐19, we found that EPO and Hpt levels were significantly lower in critical and deceased patient groups. Our study is the first study examining EPO and Hpt levels in patients diagnosed with COVID‐19.