Multi-layer puncture-resistant biaxially oriented coextruded films or tubings are disclosed for use in dilatation balloon catheters. The catheter balloons so formed comprise a first, inner layer of an orientable thermoplastic resin; a second layer of a thermoplastic inomeric olefin copolymer secured to the outside surface of the first layer; and an optional third layer of an orientable thermoplastic resin secured to the outside surface of the second layer. Processes for forming the dilatation catheter balloons herein are also disclosed.