OBJECTIVES: To compare transesophageal echocardiography (TEE) and intracardiac echocardiography (ICE) for the diagnosis of cardiac device endocarditis (CDI). BACKGROUND: The diagnosis of infective endocarditis (IE) is established using the modified Duke criteria based mainly on echocardiography and blood cultures. No previous studies compared ICE to TEE for the diagnosis of IE. METHODS: We prospectively enrolled 162 patients (72±11 years; 125 male) who underwent transvenous lead extraction: 152 with CDI and 10 with lead malfunction (control group). Using the modified Duke criteria, we divided the patients with infection into 3 groups: 44 with "definite" diagnosis of IE (group 1), 52 with "possible" diagnosis of IE (group 2) and 56 with "rejected" diagnosis of IE (group 3). TEE and ICE were performed before the procedure. RESULTS: In group 1, ICE identified intracardiac masses (ICM) in all 44 patients; TEE identified ICM in 32 patients (73%). In group 2, 6 patients (11%) had ICE and TEE both positive for ICM, 8 patients (15%) had a negative TEE but a positive ICE and 38 patients (73%) had ICE and TEE both negative. In group 3, 2 patients (3%) had ICM both at ICE and TEE, 1 patients (2%) had an ICM at ICE and a negative TEE, 53 patients (95%) had no ICM at ICE and TEE. ICE and TEE were both negative in the control group. CONCLUSION: ICE represents a useful technique for the diagnosis of ICM, thus providing improved imaging of right-sided leads and increasing the diagnostic yield as compared to TEE.