Background: the identification of a simple and effective prognosticator is crucial for high lightening and treating the potentially critical patients, to reduce the mortality rate, Serum CRP is a simple and effective prognosticator which casts light on potentially critical patients, Serum CRP has a predictive value of COVID-19. Patients and methods: This study included 328 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 Cromatest Linear chemicals S.L.U. Barcelona Spain turbidimetric method is used. Results: Female gender was more frequent (n=192, 58.5%) than Male gender (n=136, 41.5%). This study reveals a high level of CRP in 296 patients (90.2%) with a sensitivity of 90.2%, which is divided into two groups the first have CRP levels 5-100 (56.1%) and the second group has CRP levels more than 100 (34.1%), the high-level CRP was a significant biomarker for COVID-19 diagnosis or prognosis in out-hospitalized patients (Outpatients and patients under home observation), with a p-value is p < /em> is < .00001which less than 0.05. Conclusion: CRP levels were positively correlated with mild COVID-19 infection of lung lesions with a sensitivity of 90.2%. CRP levels could reflect disease severity and should be used as a key indicator for disease monitoring.