A balloon dilatation catheter having a proximal tubular member formed of high strength materials such as stainless steel with an inner lumen for directing inflation fluid through the tubular member, a double lumen distal member which is secured to the distal end of the proximal tubular member with one of the lumens in the distal member being in fluid communication and axially aligned with the inner lumen of the proximal tubular member and the other lumen which is generally offset and parallel to the first inner lumen being adapted to slidbly receive a guidewire and an inflatable balloon on the distal member. A proximal port in the proximal end of the second inner lumen is spaced at least 10 cm but not more than about 40 cm proximally from a distal port in the distal end of the catheter.