The grafting of vinyltriethoxysilane (VTES) onto polyethylene (PE) with the help of small amounts of peroxides was investigated to film-blow these modified materials. The degree of crosslinking was kept very low to achieve good melt processability and improved mechanical properties. The possibility of obtaining modified PE films with improved properties and regularly distributed crosslinking with a single processing step demonstrates the uniqueness of this study. The additive concentration was established through preliminary studies; with a batch mixer, it was possible to process the modified PE in the film-blowing operation. Water treatment of the modified films after film blowing allowed for improved properties without the processability being affected. The modification of PE was followed with mechanical, rheological, and extraction tests and with calorimetric analyses. The variations of the main mechanical properties of the films were very important from an application point of view. The elastic modulus and tear strength of the films for both extrusion directions (machine and transverse) increased with the VTES concentration increasing and even more with the addition of a small quantity of a peroxide. Some reductions of the tensile strength and elongation at break were observed, but these reductions were not considerable. (C) 2009 Wiley Periodicals, Inc. J Appl Polym Sci 114: 503-508, 2009