An atherectomy catheter comprises a flexible tube having a proximal end and a distal end, and a cutter housing secured to the proximal end. A spring tip nose cone is secured to a distal end of the cutter housing and comprises a relatively soft polymeric wall having a spring coil embedded therein. The spring tip nose cone has a controlled flexibility, generally being more flexible toward the distal tip. The spring coil inhibits collapse of the nose cone under the expected conditions of use, and the flexibility and non-collapsibility together assure that the nose cone can be introduced over a movable guide wire without substantial binding. Means may be provided for inhibiting loss of atheroma from the interior of the nose cone.