A single view, wedge, pulmonary angiogram was performed at bedside in nine patients using a Swan-Ganz catheter which had been inserted previously for other indications. Criteria for consideration of a bedside study were as follows: (1) a clinical suspicion of significant, acute pulmonary embolism; (2) the inability or inadvisability of transferring the patient for definitive studies; and (3) a Swan-Ganz catheter in situ. Seven of the nine patients subsequently died. Of five patients who underwent necropsy, three positive studies and one negative, were confirmed. No post-mortem evidence for embolism could be demonstrated in one patient with a positive study. Of the two patients who survived, one negative study was confirmed with a negative radionuclide perfusion lung scan. There was no morbidity or mortality associated with the procedure. These data suggest that this technique is safe and has a role in the early diagnosis of significant pulmonary embolism in selected critically ill patient.