Background: In December of 2019, Wuhan, a new coronavirus-caused pandemic of atypical pneumonia was reported by China. This study determined IL-6 value in disease severity assessment of COVID-19 patients without preexisting pathologies. Methods: This cross-sectional study was conducted on 100 participants. They were classified into group A included 25 patients classified as mild or moderate cases, group B included 25 patients classified as severe cases, group C included 25 patients classified as critical ill cases and all was positive PCR COVID-19 and group D (Control Group) included 25 healthy individuals. Participants were subjected to history taking, Serum IL-6 measurement using ELISA, laboratory investigations and imaging. Results: IL-6 significantly differed between the studied groups (P < 0.001). IL-6 showed significant positive correlations with age (r = 0.338, P = 0.003), SBP (r = 0.288, P = 0.012), temperature (r = 0.262, P = 0.023), respiratory rate (r = 0.729, P < 0.001), D-dimer (r = 0.704, P < 0.001), ferritin (r = 0.791, P < 0.001), CRP (r = 0.592, P < 0.001), and severity (r = 0.821, P < 0.001). Multinomial logistic regression analysis revealed that IL-6 was a significant predictor for mild to moderate covid (OR = 7.66, 95% CI = 2.212 – 26.528, P = 0.001), severe covid (OR = 17.727, 95% CI = 4.545 – 69.141, P < 0.001), and critically ill patients (OR = 24.345, 95% CI = 6.135-96.604, P < 0.001). Conclusion: IL-6 can significantly predict COVID-19 severity (mild to moderate, severe and critically ill) and mortality.