The aim of this work was the preparation of polypropylene/hydrocarbon resin (PP/HR) blends. The blends were processed by one-step feeding in a twin-screw extruder using three different kinds of hydrogenated hydrocarbon resin: Sukorez 120 (SU-120) and Sukorez 130 (SU-130), that had the same chemical structure but different molar masses and the cyclic hydrocarbon resin Hikorez 2130 (H-2130). The blends were made at 100/0, 95/5, 90/10 and 80/20 PP/HR mass ratio. After that, in a second extrusion process, were prepared films of those mixtures for further characterization. The effects of hydrocarbon resin (HR) on the thermal, mechanical and barrier properties of PP blends were investigated by differential scanning calorimetry (DSC), tensile tests and water vapor permeability.