Since June 1998, we have used an Amplatzer device whenever considered appropriate in patients with isolated defects within the oval fossa. The aim of this study was to define the total cohort of patients with isolated defects in the oval fossa seen at this hospital, so as to assess the impact of this policy on contemporary management. In the two-year period commencing 1st June 1998, 116 patients older than 6 months were seen with an isolated septal defect within the oval fossa. Mean age at closure or last review was 5.8 years, with a range from 0.5 to 20 years. In total, 42 (36%) patients were assigned to surgical closure, 25 (22%) to closure using an Amplatzer device, and 49 (42%) remained under clinical follow up. Direct referral for surgical closure occurred in 24 (21%) patients, in whom transcatheter closure was considered not appropriate after transthoracic echocardiography. Transoesophageal echocardiography was performed in 45 (39%) patients to assess suitability for closure using the Amplatzer device. Of these, 20 (44% of the group undergoing transoesophageal echocardiography) were considered unsuitable for closure in this fashion. Of these, 8 were referred for surgery and 2 with small defects were considered not to require closure. Patients undergoing closure with the device were older than the group referred for surgical closure, having a median age of 7.8 versus 3.6 years, and stayed for a shorter period in hospital. Those closed using the device stayed for 2 days, as opposed to a median of 5 days, with a range from 4 to 10 days for those undergoing surgical closure. Closure was complete as assessed by echocardiography after follow up of 1–3 months in both groups. There were no recognised complications related to insertion of the device, whereas transient postoperative morbidity occurred in 38% of those closed surgically. Insertion of an Amplatzer device was considered to be appropriate in 37% of patients older than 6 months requiring closure of an atrial septal defect in the oval fossa.