Background: By the end of 2019, coronavirus identified as a cause of pneumonia cases in Wuhan city, China. In February 2020, World Health Organization reported the disease COVID-19, which means for coronavirus disease 2019. There is a great need for rapid and accurate diagnostic tools to aid in triage of severe cases.

Aim of the work: Our study aimed to evaluate some biochemical and hematological parameters in COVID-19 patients and its relation to severity.

Patients and methods: It was a case control study, included 200 individuals which had classified into two groups. Covid group: 100 patients with Positive PCR COVID-19 infection. Control group: 100 individuals matched for age and sex and complained of diseases apart from COVID-19 confirmed by negative PCR. All patients were chosen from outpatient clinic and inpatient of Chest department of Al-Azhar University Hospital at New Damietta from March 2021 to January 2022. Evaluation of complete blood picture with differential count, inflammatory profile as CRP, ferritin and LDH together with serum protein electrophoresis were done.

Results: We found that there was markedly difference between COVID-19 group and control group as regards to WBCs, Lymphocyte and PNL/ Lymph ratio. It also found that in COVID-19 group D-Dimer, serum ferritin and LDH were highly significant increase in COVID-19 group compared to control group. Finally, serum protein electrophoresis shows significant changes in COVID-19 group compared to control groups and also shows significant correlation with severity of cases.

Conclusion: We concluded that laboratory tests may serve as adjuvant in diagnosis and following up of COVID-19 cases and using of serum protein electrophoresis may aid in early diagnosis and correlate with severity.