Pulmonary embolism is a frequent and potentially life-threatening event with uncharacteristic clinical manifestations. Diagnosis is commonly established by ventilation/perfusion scintigraphy and pulmonary angiography. Both methods, however, carry substantial drawbacks. Therefore, clinicians claim that there is a need for an accurate and non-invasive diagnostic modality. Spiral CT of the pulmonary arteries is a recent modality, that allows reliable visualization of emboli in pulmonary arteries up to fourth-order branches. This paper reviews the technical aspects, typical findings and diagnostic pitfalls of this recent technique. The potential role of spiral CT in the screening of patients with suspected pulmonary embolism is discussed and selected cases are presented.