A spiral cut transition member is disclosed for controlling the transition in stiffness of a catheter from a stiffer more pushable proximal section to a more flexible and trackable distal section and increasing kink resistance. The transition member has a spiral cut provided therein to vary the flexibility of the transition member over its length. The pitch of the spiral cut can be varied to facilitate a gradual transition in flexibility along the catheter. The transition member may be used in conjunction with any type of catheter including single-operator-exchange type catheters, over-the wire type catheters, and/or fixed-wire type catheters.