Transseptal left atrial puncture has generally been carried out under fluoroscopic control. In our experience, cardiac tamponade occurred in 3 of 83 cases during transseptal puncture for percutaneous transvenous mitral commissurotomy (PTMC) and percutaneous transvenous aortic valvuloplasty (PTAV). We tried to perform the puncture under simultaneous fluoroscopic and 2DE guidance to decrease the rate of complications. As a result, no complication has occurred in 55 cases. Furthermore, 2DE indicated that directing the puncture needle towards 4 or 5 o'clock was inappropriate, but that 3 o'clock was an appropriate direction for puncture of the fossa ovalis of a left atrium dilated because of mitral stenosis. In conclusion, transseptal left atrial puncture can safely and easily be carried out under a combination of fluoroscopic and 2DE guidance, as this procedure displays the correct position and direction of the needle tip for interatrial septal puncture.