Abstract: The multi-mode guidewire selectively allows the creation of varying degrees of flexibility at varying locations of the guidewire. An elongate coiled wire body of the guidewire is capable of assuming an arcuate shape adjacent to its capped distal end. The coiled wire body may be made less flexible by a curve control core wire which is positionable by means of a knob at its proximal end. The curve control core wire includes a region of moderate flexibility in its distal region which can be stiffened by a stiffening member. The stiffening member is positionable by a handle located at its proximal end. A method of advancing a catheter and the guidewire includes selecting a most advantageous mode of use of the guidewire for advancement.