The capacity and efficiency of the COVID-19 surveillance system in diagnosis patients by epidemiologic indicators are critical for system utility and practice. Policymakers and health managers can make effective plans to control the COVID-19 outbreak by having valid and appropriate data surveillance ability. They can also review and revise the plan, if necessary. Sensitivity, specificity, positive, and negative predictive value are important indicators for assessing the capacity of the surveillance system to diagnose cases. However, due to the low sensitivity of COVID-19 diagnostic tests and the high false-negative percentage and the long interval between the diagnosis and the confirmed result, it is better to evaluate the capacity of the surveillance system to take care of reliability indicators such as Percent Positive Agreement (PPA) and KAPPA statistics.