OBJECTIVE: In this study, we aimed to highlight the common early-stage clinical and laboratory variables independently related to the acute phase duration in patients with uncomplicated coronavirus disease (COVID-19) pneumonia. METHODS: In hospitalized patients, the acute phase disease duration was followed using the Brescia-COVID respiratory severity scale. Noninvasive ventilation was administered based on clinical judgment. Patients requiring oropharyngeal intubation were excluded from the study. For parameters to be measured at the hospital entrance, age, clinical history, National Early Warning Score 2 (a multiparametric score system), partial pressure of oxygen in arterial blood/fraction of inspired oxygen (P/F ratio), C-reactive protein, and blood cell count were selected. RESULTS: In 64 patients, age (direct relationship), P/F, and platelet number (inverse relationship) independently accounted for 43% of the acute phase duration of the disease (P < .001). CONCLUSIONS: For the first time, the present results revealed that the acute phase duration of noncomplicated pneumonia, resulting from severe acute respiratory syndrome coronavirus 2, is independently predicted from a patient's age, as well as based on the hospital entrance values of P/F ratio and peripheral blood platelet count.