Despite the publication of the Prospective Investigation of Pulmonary Embolism Diagnosis in 1990, the diagnostic evaluation of pulmonary embolism continues to be approached in an inconsistent fashion. The reasons for this are unclear but likely have to do with inadequate methods for predicting pretest probability of disease and the inconvenience and perceived risk of pulmonary angiography. Because pulmonary embolism and its treatment carry substantial risk of morbidity and mortality, a consistent approach to evaluation is desirable. This article reviews large, prospective studies that suggest that it may be unnecessary to diagnose pulmonary embolism with the certainty that pulmonary angiography allows. Finally, the article proposes an algorithm that may be acceptable to patients and clinicians alike if safety is confirmed in future prospective studies.