A stent crimping system and method for use in preparing a bifurcation catheter assembly for use in a patient. The catheter assembly includes main and side catheter branches and a stent. The stent includes a side branch aperture through which the side catheter branch extends. The stent is crimped onto the main and side catheter branches with a crimping mechanism in two crimping steps. In the first crimping step, only a distal end portion of the stent is crimped while the side catheter branch remains extending through the side branch opening of the stent and remains positioned outside of the crimping mechanism. In a second crimping step, the entire stent is crimped with the crimping mechanism.