A 59-year-old man presented with culture-negative endocarditis. Serial echocardiographic/Doppler studies disclosed progressive aortic insufficiency with resultant premature closure of the mitral valve. At the time the patient developed PMVC he was considered for emergent aortic valve replacement; ultimately, however, he was deemed inoperable because of his underlying medical problems. Surprisingly, the patient gradually improved on antibiotic therapy alone, with subsequent hemodynamic stabilization and reversion of the PMVC. This case represents the first description of reversion of PMVC in a medically treated patient with severe aortic insufficiency secondary to infective endocarditis, and underscores the importance of basing management decisions concerning aortic valve replacement in infective endocarditis upon the entire constellation of clinical findings rather than a single echocardiographic sign.