A method for placing a stent assembly in a bifurcated vessel in an animal body, such as a human, includes inserting primary and secondary guidewires from a location external of the body through the primary vessel. The second guidewire is also inserted into the secondary or branch vessel beyond a bifurcation area. The primary and secondary guidewires are then inserted into a primary stent and catheter assembly such that the assembly can move along the guidewires into and through the primary vessel to the bifurcation area where the primary stent is expanded. While retaining the secondary guidewire in the vessels, the remainder of the catheter assembly and primary guidewire are removed. Then the secondary stent, mounted on a catheter, is passed through the primary vessel using the secondary guidewire as a guide, past the bifurcation area and into the secondary vessel. There, the secondary stent is expanded to form the bifurcated stent assembly in an efficient and practical manner.