The role of lung scintigraphy in the diagnostic management of patients with clinically suspected pulmonary embolism is reviewed. Evidence is provided that a normal perfusion scan excludes clinically relevant pulmonary embolism, and that a high probability lung scan, defined as a segmental perfusion defect with locally normal ventilation, sufficiently confirms the presence of pulmonary embolism in the majority of these patients. Furthermore, this review assesses the possibility of non-invasive tests for the diagnosis or exclusion of venous thromboembolic disease as a means of avoiding pulmonary angiography in patients with lung scan outcomes that are neither normal nor high probability.