A case of early autograft endocarditis occurring three weeks after a Ross operation is described. The origin of the infection appeared to be the proximal suture line of the autograft and the pathology included subvalvular destruction of the autograft, a pseudoaneurysm between the autograft and the left atrium, and a fistula to and a vegetation in the roof of the left atrium. The valve cusps were unaffected and there was only slight autograft insufficiency (grade I-II). The autograft was removed and successfully replaced with a homograft.