A dilator having a retractable needle is disclosed. The dilator includes an elongated dilator body having a proximal end, a distal end and at least one lumen longitudinally extending therethrough. A handle is mounted at the proximal end of the dilator body, and a control button is moveably connected to the outside of the handle. The needle extends through the lumen and has a distal end comprising a needle tip section. An arm attached the control button to the needle. Distal movement of the control button causes the needle to move from a retracted position, wherein the needle tip is disposed within the lumen of the dilator body, to a protruding position, wherein the needle tip protrudes beyond the distal end of the dilator body. In use, the distal end of the dilator is inserted into the right atrium of a patient, a position on the atrial septum to be punctured is located with the distal end of the dilator body, the needle tip is advanced beyond the distal end of the dilator body, and the atrial septum is punctured with the needle tip.