Background: Multislice computed tomography not only improves the detection and characterization of parenchymal abnormalities but also increases the accuracy of diagnosis. Objective: To study and differentiate multidetector computed tomography findings and the pathologic characteristics in different pulmonary ground-glass opacity causes. Patients and methods: Thirty patients referred from the Chest Department, Zagazig University Hospital to the Radiology Department during the period from November 2018 to December 2019, were included in this cross-sectional trial. Diagnosis of GGO is based on careful history taking and clinical data, restrictive or obstructive pulmonary defect, and conclusive radiographic as well as histopathologic findings.  Results: parenchymal lung diseases were predominant as seen in 24 patients accounting for 80 % of such patients while vascular diseases were responsible for ground-glass attenuation were only 6 patients accounting for 20%. The commonest diagnosis for the diffuse pattern of ground-glass opacity was interstitial lung diseases (16.7%), followed by pulmonary fibrosis (13.3%), cardiogenic pulmonary edema (10%), then pulmonary hemorrhage (6.7%), and lastly pulmonary hypertension with (3.3%). In the patchy pattern of ground glass, the commonest diagnosis was infectious pneumonia (10%), followed by post-irradiation and post patchy and diffuse patterns showing restrictive dysfunction (high FEV1/FVC and FVC is reduced) and the nodular pattern shows mixed dysfunction (low FEV1and low FVC). Conclusion: we offer a diagnostic approach for the evaluation of ground-glass patterns in HRCT of the chest based on all previous consensus data. It could help to narrow the list of differential diagnosis and reach the most accurate one