A medical balloon (10) of a balloon catheter assembly (70) includes a balloon wall (22) formed of at least two layers (30, 32). The first layer (30) is made of an impervious polymeric material. The second layer (32), which is integral with the first layer (30) is made of a radiopaque and/or echogenic material and a polymeric material. In the preferred embodiment, there is provided 60 to 80% by weight of radiopaque material in the second layer (32). It has been found that these concentrations of radiopaque material provide good visibility of the balloon under ultrasonic imaging.
