Background: The coronavirus disease "COVID-19" was reported in 2019 as an outbreak in Wuhan, China, and categorized as a pandemic disease in 2020 with severe complications. Objective: This study aimed to test the effects of COVID-19 infection on blood parameters and to assess these effects with disease progress. Patients and Methods: 120 patients with COVID-19 in Al-Amal Specialized Hospital for Communicable Diseases in Al-Najaf Al-Ashraf province with 30 healthy (control) individuals of both genders were included in this study. Blood parameters (complete blood count, PLT and ferritin) were measured for 3 weeks from the 1^st day of hospitalization. Results: The study revealed significant differences in the hematological parameters for COVID-19 patients in comparison with the control group and these variations increased with the progress and severity of the disease. No significant variations were noticed in Hb and HCT of patients compared to control, but these parameters decreased with disease progression. Conclusion: A comparison of COVID-19 patients with healthy individuals revealed significant differences in hematological parameters, which became more pronounced with the progression and severity of the disease.