Aim. To explore the potential relationship between NLR and micronutrient deficiency in patients with severe COVID-19 infection. Methods. Sixteen patients were categorized into the mild group (mild COVID-19) and severe group (severe COVID-19) based on the guideline of the management of COVID-19. The lactate dehydrogenase (LDH); superoxide dismutase (SOD), the inflammatory markers (neutrophil lymphocyte ratio (NLR)), erythrocyte sedimentation rate (ESR), c-reactive protein (CRP), selenium (Se), iron (Fe), zinc (Zn), nickel (Ni), copper (Cu), chromium (Cr), cadmium (Cd), arsenic (As), and manganese (Mn) were measured in the blood. Results. Compared to the mild group, the NLR ( P < 0.05 ) and the level of Se ( P < 0.01 ), Fe ( P < 0.05 ), and Zn ( P < 0.05 ) were significantly decreased in the severe group. The level of Se, Fe, and Zn was significantly correlated to NLR levels. Furthermore, close positive correlation was found between NLR and severity of COVID-19. Conclusion. The micronutrient deficiency in the blood is associated with NLR in the severity of COVID-19 patients.