In the present report, the author deals with chromic acid pretreatment on the surface to be coated. Several comparative adhesion tests using three types of polyethylene sample panels (plain, sanded, and chromic acid treated) are described. In evaluating adhesion, a tensile shear strength test, cross cut adhesion tape test, and scratch adhesion tape test are used. It was found that chromic acid treatment was highly effective in improving adhesion of various paints with polyethylene surface and further that among the paints the best result is achieved with epoxy resin paint.