Transesophageal echocardiography (TEE) is used widely in the decision-making process during aortic valve surgery. In our center, the Toronto Stentless Prosthetic Valve (TSPV) is the most commonly implanted stentless bioprosthesis. Use of this prosthesis involves complex anatomic spatial relationships between the commissures of the stentless valve, the annulus and sinotubular junction (STJ) of the aorta. Intraoperative TEE performed before cardiopulmonary bypass (CPB) allows the surgeon to study these relationships and to confirm implantation feasibility by measuring diameters of the aortic annulus and STJ, and matching their sizes. After CPB, TEE can be used promptly to verify prosthesis function. In our experience, intraoperative TEE aids the decision-making process of TSPV implantation by helping to select patients suitable for the stentless valve, predicting prosthesis size, and checking for TSPV function.