Polyethylene films were irradiated through a mask with high-energy argon ions to activate the surface for grafting. Acrylic acid was graft polymerized onto the irradiated region of the polyethylene surface. The grafted surface was characterized by using FT-IR and XPS. Patterned grafting of acrylic acid on the polyethylene surface was finally confirmed by a fluorescence labeling method. Copyright (C) 2008 John Wiley & Sons, Ltd.