Aim: In this study we aimed to investigate diagnostic usefullness and optimal cut-off values of monocyte, mean platelet volume (MPV), eosinophil, neutrophil lymphocyte ratio (NLR), platelet lymphocyte ratio (PLR), monocyte lymphocye ratio (MLR), red blood cell distribution width (RDW) in laboratory confirmed Covid-19 cases with and without pneumonia who were totally healthy before being infected with Covid-19. Materials and Methods: Data of a total 10000 patients who were admitted to hospital with complaints apropriate with Covid-19 in six months (March–Agust 2020) interval and underwent SARS-CoV-2 Polymerase Chain Reaction (PCR) investigated. Out of 10000 patients we included only previosly healthy 174 patients with Covid-19 pneumonia, 144 SARS-CoV-2 positive but no pneumonia and SARS-CoV-2 PCR negative 156 healthy controls. The laboratory results and demographic findings were collected from patient files retrospectively before undergiong treatment for Covid-19. Results: We found wbc levels lower in Covid-19 patients with pneumonia (p <0.001 vs healthy), as well as neutrophil (p <0.001 vs healthy), Monocyte (p <0.001 vs healthy and Covid-19 without pneumonia), Eosinophil (p <0.001 vs healthy and Covid-19 without pneumonia) and Platelet count (p <0.001 vs healthy). MLR remained higher in patients without pneumonia (p <0.001 vs Covid-19 with pneumonia and healthy controls) as well as PLR (p <0.001 versus Healthy). Conclusion: In the light of the obtained results, decrease in wbc, neutrophil, monocyte and eosinophil levels support the diagnosis of Covid-19 pneumonia on the other hand increase in MLR and PLR may indicate Covid-19 without pneumonia. Keywords: Covid-19 pneumonia, esoinophil, monocyte