Abstract: An apparatus and method is provided for stenting bifurcated vessels. A main-vessel stent and delivery system is provided for implanting a stent in the main vessel of a bifurcated vessel, wherein the main-vessel stent has an aperture bordered by closed stent cells that aligns with the opening to a side-branch vessel to permit substantially unobstructed blood flow between the main vessel and the side-branch vessel. The delivery system includes a catheter assembly having distal and proximal balloons separated by a positioning guide wire exit port located at the distal end of the catheter. The catheter assembly is advanced over a pair of guide wires for delivering, appropriately orienting, and implanting the main-vessel stent.