Abstract: The guidewire extension wire and connector assembly comprises: a guidewire extension wire having a distal end portion including, extending toward a distal end of the guidewire extension wire, a break-away neck, a reduced-in-diameter stub section and a larger-in-diameter distal stub end; an inner sleeve having an inner end fixed to the guidewire extension wire proximally of the break-away neck and an outer end extending to the larger-in-diameter distal stub end; an outer sleeve having an inner end thereof fixed to the larger-in-diameter distal stub end; and, a fixing mechanism within an outer end of the outer sleeve adapted to engage a generally cylindrical reduced-in-diameter proximal stub end of an initially inserted guidewire.