To assess the incidence of aseptic thrombotic endocardial vegetations (TEV) after pulmonary artery catheterization with Swan-Ganz catheters we reviewed all autopsy reports for a two-year period in our hospital. In 413 autopsies there were five instances of aseptic TEV: 3 in 88 patients with Swan-Ganz catheters, 1 in 120 patients with central venous catheters, and 1 in the 205 patients without central vascular catheters. The incidence of TEV is significantly greater in patients with Swan-Ganz catheters than in other patients.