Background The safety and efficacy of transesophageal echocardiography (TEE) during congenital heart surgery is well established. The economic costs and benefits associated with its routine use in this setting are, however, uncertain. We sought to analyze the impact that routine intraoperative TEE had on echocardiographic costs in the setting of congenital heart surgery. Methods and Results A retrospective, case-controlled analysis of echocardiographic costs during the operative and postoperative periods was performed for 63 children undergoing elective, complex intracardiac repair. Similar analysis was performed for a smaller group of patients undergoing simple repairs. To ascertain whether any additional cost savings was realized through the use of TEE, we documented the impact that operative TEE had on altering surgical strategy as well as whether TEE use was associated with any intraoperative complications. Despite the additional expense, routine TEE, in the setting of complex repair, resulted in no significant increases in echocardiographic costs, suggesting the superior information provided may in fact reduce the need for additional postoperative studies in the intensive care setting. Although no child required a return to cardiopulmonary bypass, surgical therapy was altered by TEE findings in 2 (3%) of 63 patients. Complications were rare and self-limited, usually occurring with positioning of the probe in smaller patients. Conclusions The findings of improved surgical outcomes in a percentage of patients, coupled with the lack of any significant increment in echocardiographic costs, confirm that intraoperative TEE is a beneficial and cost-effective intervention in children requiring complex cardiac repair. (Am Heart J 1999;138:771-6.)