Naoum FA, Ruiz ALZ, de Oliveira Martin FH, et al. - Researchers investigated the diagnostic as well as the prognostic implications of WBC and cell population data (CPD) abnormalities associated with coronavirus disease 2019 (COVID‐19) at disease onset. Participants were 100 COVID‐19 patients visiting the emergency department and subsequently discharged (n = 49), admitted (n = 51) or deceased (n = 22), as well as 47 healthy individuals. Baseline WBC counts and CPD data were studied in these patients. According to the ROC curve analysis, there was a good performance of lymphocyte counts and neutrophil counts in predicting COVID‐19 diagnosis and admission for COVID‐19, respectively; monocytes volume showed good performance in predicting COVID‐19 diagnosis. Based on the findings, an improved diagnostic description as well as assistance in distinguishing between severe and nonsevere presentations can be provided by WBC counts and CPD parameters at disease onset in COVID‐19 patients.