To assess the diagnostic and therapeutic management of patients with clinically suspected pulmonary embolism. A prospective survey of the management of patients with clinically suspected pulmonary embolism was carried out in two teaching hospitals in Amsterdam, without the knowledge of the attending physicians. Use and timing of lung scintigraphy and other tests for venous thromboembolism, therapeutic consequences and duration of hospitalization were evaluated. Of 89 outpatients and 116 inpatients, 97% of patients underwent lung scintigraphy. Lung scan results were normal in 51% of outpatients and 20% of directly admitted patients; high probability in 10% and 22% and non-diagnostic in 39% and 58%, respectively. Twenty-two outpatients were subsequently admitted (1 normal, 9 high-probability and 12 non-high-probability lung scans). Pulmonary angiography and tests for deep vein thrombosis were performed in 7 (10%) and 21 (29%) of admitted patients with a non-diagnostic lung scan outcome, respectively. Of 138 admitted patients, 75 (54%) received heparin for 5 or more days. All patients with high-probability lung scans and none with a normal lung scan received long-term anticoagulants. Of patients with non-diagnostic lung scans, therapeutic decisions were mainly based on clinical grounds, and 44% were prescribed oral anticoagulants. The median duration of hospitalization was 6 days, 14 days and 13 days for patients with a normal lung scan, a non-diagnostic lung scan and a high-probability lung scan outcome, respectively. Diagnostic delay in directly hospitalized patients results in anticoagulation of patients without pulmonary embolism and excessive hospitalization. Guidelines for the diagnostic management of patients with non-diagnostic lung scans are urgently required.