A stenotic dilitation device includes a plurality of elongated atherotomes with cutters embedded in a substrate mounted on the outer surface of a flexible balloon along predetermined crease lines. The atherotomes are aligned along the longitudinal axis of the catheter. The ends of the balloon are attached to a hollow catheter tube over fluid ports in the catheter which establish fluid communication between the catheter and the internal chamber of the balloon. Fluid flow into and out of the chamber will inflate and deflate the balloon. When the balloon is deflated, retraction of the atherotomes toward the longitudinal axis of the catheter causes the creases and lines to form flaps of the balloon membrane material between adjacent atherotomes. In such deflated configuration, the flaps, rather than the cutters of the atherotomes, contact the vessel wall as the device is manipulated into position adjacent a stenotic site. On inflation of the balloon at the stenotic site, the atherotomes are urged against the stenosis to incise the stenosis. The incisions relieve pressure in the wall of the vessel and thus enhance dilation of the vessel by the balloon. After dilation, the balloon is deflated and the device is removed.