Radiographic examination is a common method for diagnosis of pulmonary diseases but it is not always adequate for accurate diagnosis. Therefore, an advanced imaging method as computed tomography (CT) was used in this study for veterinary purposes. This study aimed the comparison of the two imaging methods for evaluation of pulmonary diseases in dogs. 20 dogs of various breeds, age and sex with complaints of lung disease made up the materials of the study. Following the patient history and clinical examination, radiographic examination and CT examination were performed and the outcomes were evaluated. Pulmonary nodules/masses or calcified foci in 12 patients, pleural effusion and pneumothorax in 4 patients, pulmonary edema in 2 patients, tracheal collapse and megaesophagus in two patients were diagnosed by using both radiographic and CT examination. As a conclusion, radiographic examination provides an initial diagnosis for severe diseases and can be used as first imaging modality for lung diseases, but CT has superiority over radiography due to its ability to provide cross-sectional images and more accurate diagnosis.