Grafting of poly(acrylic acid) (PAA) onto an aluminum surface was successfully achieved by free radical polymerization of acrylic acid using typical radical initiators, benzoyl peroxide and 2,2'-azobisisobutyronitrile. Both spotlike and brush morphologies were achieved. A complete coverage of PAA on an aluminum surface was then achieved by using a thermal chemical vapor deposition process. The PAA thickness was determined by ellipsometry and the superficial chemical composition by X-ray photoelectron spectroscopy (XPS). Grazing angle Fourier transform infrared (FTIR) spectroscopy confirmed the presence of carboxylic acid groups on the surface, and the contact angle measurements revealed a decreasing free surface energy of aluminum due to the polymer surface covering.