Introduction: At the end of the year 2019 a novel virus named SARS-CoV-2 caused Coronavirus Disease 19 (COVID-19), manifesting as lung infection which can result in severe pneumonia. The gold standard for diagnosis of the virus is the detection of viral RNA through reverse transcriptase PCR (RT-PCR). Materials and Methods: This study is a retrospective analysis of diagnostic yield of chest imaging modalities in the diagnosis of COVID-19 in patients admitted to the Imam Khomeini hospital, Tehran, Iran during march 2020 until July 2020. Results: 204 hospitalized patients with a mean age of 58.5 years, diagnosed with COVID-19 were enrolled in this study, who had their disease confirmed by PCR. About 20% of patients had normal O2 Saturation (above 93%) and 80% had low O2 Saturation. Also 70% of patients were hospitalized to the ICU. Among investigated patients, 87.6% had abnormal findings in their CXR. Also, 97.1% of patients had abnormal CT-Scan. In this study, the sensitivity of the CXR in the diagnosis of COVID-19 was 87.5% (CI 95%, 83 to 91) and the sensitivity of the chest CT-Scan was 97.1% (CI 95%, 94.8 to 99). Discussion: Utilizing CXR as a first-line imaging modality is recommended in many countries and clinical settings and chest CT-Scan is mainly reserved for other additional roles. This study reveals a CXR sensitivity of 87.5% which is in accordance with the recent literature (69-90%).