Paraprosthetic leaks are a postoperatively complication recurring with a frequency from 15 to 30%, and mostly in the mitral than in the aortic position. Transthoracic echocardiography can suspect prosthesis valve dysfunction, but for both diagnosis and evaluation of the paraprosthetic dysfunction severity, transesophageal study is required. In this report a mitral paraprosthetic dehiscence was diagnosed using a miniaturized, 10 F, monoplane probe inserted through nasal way. This technique, that do not require topical and general anesthesia, appears to be well tolerated providing an accurate and more comfortable examination.