Pulmonary vein isolation (PVI) guided by circumferential mapping has been established as a curative treatment of atrial fibrillation. In the PVI technique, two transseptal catheters are necessary for mapping and catheter ablation. The one-puncture, double-transseptal catheterization manoeuvre is generally used in the PVI technique. However, to the best of our knowledge, there have been no reports describing transseptal manoeuvre in detail. In this article, the manoeuvre to achieve double-transseptal catheterization easily and safely is described. © The European Society of Cardiology 2007. All rights reserved.