The clinical outcomes of 183 patients with suspected pulmonary embolism (PE) and a "low probability of PE" interpretation of aerosol-perfusion scintigrams were reviewed. Based in part on the scintigraphic findings, 173 of the patients (94.5%) were not treated with anticoagulants. Over a mean follow-up period of 8.4 months, only one patient (who was from the untreated group) had clinical evidence of PE. These results suggest that a low-probability interpretation of the aerosol-perfusion scintigram is generally reliable and a suitable indicator for clinical decision making in patients suspected of having PE.