Background: Intermediate type atrioventricular septal defect is less frequent than complete or partial atrioventricular septal defect, and is rarely encountered in the elderly and the utility of three dimensional transesophageal echocardiography in the diagnosis has not been reported to date.
Case Presentation: In this case report, we described a rare case of an intermediate atrioventricular septal defect in an adult patient and we showed the valuable utility of real time 3D transesophageal echocardiography in the diagnosis and future surgical planning. The patient was referred to a tertiary center for an elective surgical repair.