Pulmonary radiographs are essential adjuncts to the evaluation and diagnosis of suspected pulmonary disease. In the intensive care unit, radiographs are useful to confirm correct positioning of diagnostic and therapeutic devices. Patterns seen on the radiograph may be within broadly normal limits or may be interpreted as abnormal, especially when placed in the clinical context of a specific patient's problem. The description abnormal can be related to both nonspecific and specific radiographic patterns of disease. Nonspecific radiographic patterns of disease include location of disease, temporal course of disease, pleural abnormalities, hyperinflation, extra-alveolar air, atelectasis, bronchiectasis, and vascular disease. Specific radiographic patterns of disease are discrete anatomic structures seen on a radiograph, for example, cavitary and cystic disease. The interpretation of nonspecific and specific radiographic patterns is useful in diagnosis, selection of treatment, and monitoring of the course of disease and the patient's response to treatment.