Objective: Transesophageal echocardiography (TEE) is indicated for suspected atrial septal pathology and for monitoring of interventional procedures such as an atrial septal defect (ASD) closure during cardiac catheterization. Transesophageal echocardiography also helps to demonstrate postoperative complications and residual defects of complex congenital cardiac anomalies. Methods: Transesophageal echocardiography was performed in 112 pediatric patients with or suspected atrial pathology at our institution between 1999-2002, using the standard techniques. The mean age was 8.7 ±4.2 years. Results: In 45 of 112 children the suspected atrial defects were confirmed with the TEE. Patent foramen ovale was correctly predicted in 13.4% of patients by TEE, but only in 8.7% of patients by echocardiography. Multiple ASD’s were correctly defined in 4.1%, and high venosus defects were documented in 6,1% of children by the TEE. We used TEE in 13% of patients for detecting atrial vegetations in patients with possible endocarditis, and evaluation of the postoperative care of atrial surgery such as Fontan or Senning operations and total correction of abnormal pulmonary venous return. Successful transcatheter closure of 7 ASD's was accomplished under TEE guidance. Conclusion: Transesophageal echocardiography allows a much more detailed evaluation of atrial morphology than transthoracic echocardiography even in infants. Transesophageal echocardiography is also indicated during interventional procedures and postoperative evaluation of the atrial pathology.