A small diameter wire guide for medical procedures. The wire guide includes a mandrel of metallic superelastic material, such as nitinol, having a diameter less than 0.020 inches and which completes its transformation to austenite at a temperature of about 14.degree. C. The mandrel has a constant diameter over a majority of its length and includes a number of tapered portions and reduced-diameter portions in its distal region. A flexible radiopaque platinum coil is attached at the distal region of the mandrel and coaxially surrounds a portion of the distal region. A smoothly rounded tip is attached to the distal tip of the mandrel and coil and serves to shield the distal end of the coil during the insertion procedure into the patient.