Background: Creatine kinase (CK), which is a marker of muscle damage, was also often found to be elevated in deceased COVID-19 patients and those with severe disease, Therefore, higher CK could be used as a prognostic marker to indicate a more severe clinical picture of COVID-19. Patients and methods: This study included 225 out-hospitalized patients with confirmed COVID-19 infection, these study subjects were randomly selected irrespective of the age group and both genders were included, Assay procedure as manufactory instructions and Reagents of Spectrum diagnostics, optimized DGKC/IFCC liquid reagent, Egypt are used. Results: This study showed male gender was more frequent (n=135, 60%) than the female gender (n=90, 40%). This study reveals high serum CK levels in 45 patients (20%), which has a sensitivity of 20% as a biomarker for COVID-19 diagnosis in out-hospitalized patients (Outpatients and patients under home observation), with a p-value is Conclusion: CKhas a sensitivity of 20% in out-hospitalized patients (Outpatients and patients under home observation), thus elevated CK is best used as a rule-in test rather than a rule-out test.