Objectives : The relationship between immunity and trace elements levels is well known. We aimed to estimate the association of serum trace elements with severity and outcomes in the Coronavirus Disease-2019 (COVID-19) patients. Methods: In this single-centered, prospective, observational study, we enrolled 114 patients admitted to severe intensive care units (ICUs) and corresponding 112 sex and aged-matched non-ICU ward patients. Demographic data, clinical characteristics, and outcomes were all collected. We analyzed serum levels of zinc (Zn), copper (Cu), selenium (Se), and manganese (Mn) in both severity groups. Results : The serum levels of Cu, Se, and Mn in both groups were within the normal range while Zn serum levels were lower than the normal values. Based on these findings, Zn, Cu, Se, and Mn serum levels were not associated with disease severity ( P > 0.05). While we found Zn serum levels were strongly associated with patient outcomes ( P = 0.005). Our results indicated lower Mn serum levels were associated with age more than 55 years ( P = 0.006). Our results were not in favor of a causal relationship between serum trace elements levels and disease severity. Conclusion : We found Zn level as a strong indicator for patients’ outcomes that can be considered for monitoring of patients’ prognosis. Nutritional measures or supplementation can help reduce poor outcomes caused by low Zn levels in Iranian COVID-19 patients.