The aim of this study was to assess the value of the routine multiplane transoesophageal echocardiography (TEE) in the early postoperative period after mitral valve replacement with a Saint Jude Médical (SJM) mechanical prosthesis. This prospective work enrolled 56 patients who have been operated between September 1999 and September 2001, all these patients had a multiplan TEE after 14.7 days (8-29 days) of post-operative. The effect of peri-prosthetic leaks was 59%. They were always minimal and asymptomatic. 68% of them disappeared at the late exam. An asymptomatic intermittent blockage of an leaflet had been noted in one patient. It appears to us today indispensable to achieve a systematic TEE in the early post operative period after mitral valve replacement. This exam remains little aggressive and comfortably supportable by the patient in look of information brought.