In contrast to the development of new drugs, strict guidelines for the development of new diagnostic methods do not exist. A diagnostic test can be made available without proper evaluation of its clinical utility, which can lead to its premature introduction and inappropriate use. In this review suggestions are made regarding the criteria that should be met during the various phases of development of new diagnostic techniques. It is suggested that a new diagnostic test should only be implemented in routine clinical use after all phases of development have been properly performed with good results. Several diagnostic tests for pulmonary embolism (pulmonary angiography, ventilation-perfusion scintigraphy, D-dimer assays, and spiral computed tomography), and the studies evaluating them, are thereafter reviewed. It is concluded that present pulmonary angiography and ventilation-perfusion scintigraphy are the only properly evaluated diagnostic tests for pulmonary embolism. Although new developments, such as D-dimer assays and the spiral computed tomographic scan are certainly promising, further studies are needed to determine their real value and safety in the diagnostic work-up of patients suspected of pulmonary embolism.