Computed tomography (CT) is today a fundamental technique for thoracic imaging, a logical direct extension of the standard chest x-ray. Since the early 90s, volume-acquisition CT has greatly improved the performance of the conventional technique. After replacing lung and bronchial tomography, the technique has greatly contributed to the reduction in the number of diagnostic conventional angiographies. Certain decisional algorithms have been totally changed, particularly for the diagnosis of pulmonary embolism. In addition, technological advances offer new perspectives, particularly in the field of morphofunctional imaging. There are still many indications for CT and new applications can be expected. Possible drawbacks related to radiation dose and injection of contrast agents must be kept in mind.