Purpose: To detect the frequency of hematological changes in Covid-19 patients at king Abdul Aziz hospital, Makkah, Saudi Arabia; to compare the outcome of patients with or without hematological changes. Methods: This retrospective study included 537 patients. They were 0.6% asymptomatic, 22.9% mild to moderate, 31.1% severe, and 45.4% critical. According to the hematological results, patients were divided into normal, high, and low groups. Results: Anemia was found in 50.9%, 26%, 21.4%, and 1.7% of critical, mild to moderate, severe, and asymptomatic cases, respectively.  Polycythemia was detected in 16.7% and 83.3% of mild to moderate and critical cases, respectively. Thrombocytopenia was found in 44.4%, 30%, 25.6% of critical, mild to moderate and severe cases, respectively. Neutropenia was found in 40.9%, 36.4%, and 22.7% of critical, mild to moderate and severe cases. Neutrophilia was found in 58.2%, 24.1%, and 17.7% of critical, severe, and mild to moderate cases. Lymphopenia was found in 51%, 29.3%, 19.4%, and .3%. of critical, severe, mild to moderate and asymptomatic patients. Monocytopenia was found in 55%, 30%, and 15% of critical, severe, and mild to moderate cases, respectively. Monocytosis was found in 59.3%, 25.4%, and 15.3% of critical, mild to moderate, and severe cases.  The risk of death was 15.2, 2.4, 2.6, 1.9, 2.9, 2.1, 2.1 times higher in those with polycythemia, neutrophilia, monocytosis, lymphopenia, monocytopenia, diabetes, and age over 65, respectively. Conclusion: Neutrophilia, monocytosis, lymphopenia, monocytopenia, and polycythemia, diabetic patients, and age over 65 are independent predictors for death.