A catheter guide wire designed for use in guiding a catheter to a target site along a tortuous vessel path. The guide wire has a relatively long, torqueable proximal wire section, a more flexible intermediate section, and a most flexible distal end section designed to be advanced across sharp-bend vessel junctions. The intermediate section has greater lubricity than the adjacent proximal and distal sections. The greater frictional coefficient in the distal end segment acts to anchor the end of the wire in a branch vessel, when the guide wire has been advanced across the sharp-bend vessel junction, and the catheter is threaded axially over the wire, while the more lubricious surface of the intermediate section gives reduced sliding friction within the catheter during such advance. The invention also includes a catheter device containing the guide wire and catheter.