A balloon catheter includes a one-piece extrusion having inner and outer tubular walls, where the inner tubular wall defines a wire guide lumen, and a clearance extending between the inner and outer tubular walls forms an inflation lumen. A balloon is attached to the outer tubular wall and to the inner tubular wall, such that the inflation lumen is in fluid communication with the balloon and the wire guide lumen extends through the balloon. A method of making the balloon catheter is also disclosed.