In the past six years, 35 patients with thermal injuries have died with a diagnosis of endocarditis. The cause of death in 21 of the 22 patients with acute bacterial endocarditis (ABE) was directly related to complications arising from the ongoing sepsis. In only three cases was the diagnosis considered pre-mortem. The endocarditis was located in the right heart in 18, left heart in 9, and both sides in 8 cases. Associated venous thrombi were present in 14 instances, and 10 of these were septic thrombi. Staphylococcus was the primary organism in the blood in 17 of 22 patients with ABE. Clinically audible murmurs were present in only two patients. In no instance was ABE superimposed upon previously existing valvular disease. ABE can serve as a silent source of sepsis in the burn patient. The diagnosis should be suspected with persistantly positive blood cultures, especially for Staphylococcus aureus, in any burn patient in whom no other foci of sepsis can be identified. Vigorous methods of diagnosis and specific treatment are recommended.