Endocarditis is a rare manifestation of disseminated Histoplasma capsulatum infection. A 22-year-old man presented with a seven month history of fever, weight loss, and progressive aortic insufficiency. The diagnosis of H. capsulatum was suggested by a diagnostic rise in complement fixation titers and positive echocardiographic findings. The diagnosis was confirmed prior to surgery by positive bone marrow culture. Progressive congestive heart failure necessitated replacement of the aortic valve which subsequently grew H. capsulatum. In this case, a combination of amphotericin B therapy and valve replacement was curative.