Atrial transseptal catheterization is usually performed with fluoroscopic guidance of the needle. We report our experience with both fluoroscopic and transesophageal guidance in patients who would otherwise have been at risk by using only fluoroscopy. A total of eleven procedures were performed during a 4 year period. The relative contraindications (some patients had several contraindications) included prior valve replacement (5 patients), prior myocardial revascularization (4 patients), severe dilatation of the left atrium (4 patients), severe dilatation of the ascending aorta (4 patients), and kyphoscoliosis (3 patients). All eleven patients had the transesophageal guided transseptal catheterization performed without complications and without significantly prolonging the procedure. The results of this preliminary, small, and retrospective study suggest that transesophageal echocardiography may enhance the safety of transseptal catheterization in high risk patients. Further prospective studies are needed.