Timely diagnosis and subsequent appropriate intervention is important in respiratory diseases. Chest radiograph is the most commonly performed radiologic examination and is the imaging study that the majority of non-radiologist physicians are most likely to encounter in their clinical practice. Chest radiography, however, can be very complex and difficult to interpret accurately due to abnormalities that might be quite subtle. Failure to detect lung cancer on the chest radiograph, which has become one of the most frequent causes of missed diagnoses in radiology, is a major cause that brings up medicolegal suits. There are no reliable radiographic criteria to distinguish lung cancer from benign diseases. Being knowledgeable about thoracic imaging will help to minimize errors. The diagnosis of lung cancer is commonly delayed because of masking by a tuberculosis lesion. In diagnosing tuberculosis, clinicians should be aware of endobronchial tuberculosis, anthracofibrosis, multidrug resistant tuberculosis, and non-tuberculous mycobacterial diseases. If pneumonia was not resolved, endobronchial lesions such as a foreign body or cancer, bronchioloalveolar cell carcinoma, and atypical pathogens might be considered. In patients with chronic coughing, eosinophilic bronchitis also should be suspected in addition to postnasal drip syndrome, cough variant asthma, and gastroesophageal reflux disease. Most common pitfalls can be avoided by physicians who are familiar with diverse patterns of respiratory disease in diagnosis. Through an increased familiarity with variable manifestations of pulmonary diseases and a high index of suspicion, the diagnosis of respiratory diseases will be improved.