Aim: We aimed to determine the prognostic values of the National Early Warning Score 2 (NEWS2) and laboratory parameters during the first week of COVID-19. Materials & methods: All adult patients who were hospitalized for confirmed COVID-19 between 11 March and 11 May 2020 were retrospectively included. Results: Overall, 611 patients were included. Our results showed that NEWS2, procalcitonin, neutrophil/lymphocyte ratio and albumin at D0, D3, D5 and D7 were the best predictors for clinical deterioration defined as a composite of ICU admission during hospitalization or in-hospital death. Procalcitonin had the highest odds ratio for clinical deterioration on all days. Conclusion: This study provides a list of several laboratory parameters correlated with NEWS2 and potential predictors for clinical deterioration in patients with COVID-19.