Three patients with proved periannular lesions of the aortic valve were studied by transesophageal 2-D and Doppler Echocardiography. In all three patients, surgery confirmed the presence of mycotic aneurysm associated with aortic valve endocarditis and postoperative false-aneurysms around the prosthetic aortic valve and graft. Transthoracic echocardiographic images did not clearly display periannular lesions because of reverberations or side lobe of the calcified and prosthetic valve. However, using transesophageal 2-D and Doppler echocardiography, we were able to identify the locations and sizes of the false-aneurysms around the aortic valve in two cases. In addition the disruption of coronary graft after Bentall's operation could be diagnosed by recording the abnormal flow in the periductal false-aneurysm. We conclude that transesophageal echocardiography is an important technique for diagnosis and follow-up study of patients with aortic periannular lesions.