Background: In critical care medicine, lung ultrasonography (LUS) has become more widely utilized as a trustworthy method for assessing lung diseases. Since COVID-19 pneumonia lesions have a predominant peripheral distribution, LUS detection is more appropriate. Objective: This study was aimed to assess the role of LUS in early diagnosis of COVID-19, as well as severity assessment of COVID-19 patients using CT chest as a gold standard. Patients and methods: Patients in this prospective cohort study were complaining of symptoms raising suspicion of SARS-CoV-2 infection and referred from chest emergency departments. Ultra-sound and CT were done for all patients and finding were correlated in the two modalities with estimation of the severity score. Results: out of 242 patients with CT chest findings positive for COVID-19 infection, 232 patients demonstrated positive LUS findings for COVID-19. Our study revealed the sensitivity of LUS up to (99.15%), specificity (100%), PPV (100%), NPV (80%) and accuracy (99.17%). Conclusion: It could be concluded that LUS could show pulmonary manifestations indicative of COVID-19 in symptomatic patients with high diagnostic accuracy comparable to CT chest.