Background: Transoesophageal echocardiography has become a powerful tool in the diagnosis and management of children with congenital cardiac malformations. Unlike adults, children will not tolerate transoesophageal echocardiography under light sedation. This study was undertaken, therefore, to evaluate the safety and efficacy of deep sedation with propofol for transoesophageal echocardiography in children examined in an outpatient setting. Methods: This is a retrospective study of patients undergoing transoesophageal echocardiography with propofol given in bolus aliquots to achieve a level of sedation adequate to insert the transoesophageal echocardiographic probe and maintain sedation throughout the procedure. Results: We included a total of 118 patients, 57% being male, with a mean age of 12.9 years. Adequate sedation was achieved using a mean propofol dose of 8.3 milligrams per kilogram, with the dose per kilogram decreasing concomitant with increasing weight of the patient. Patients less than two years of age were intubated for the procedure. There were no clinically significant changes in cardiac function or haemodynamics. Non-intubated patients received supplemental oxygen prior to, or just after, the onset of sedation, with transient hypoxaemia observed in one-fifth. Complications were rare, with minor problems occurring in 7.6%, and major ones in 4%. Conclusions: Transoesophageal echocardiography can be performed on an outpatient basis in children with a wide spectrum of congenital cardiac malformations, and propofol is an ideal sedative agent in this setting. Although not common, preparations must be made for significant haemodynamic and respiratory complications. In our study, we intubated all the children under 2 years of age.