Polymerizations of methyl methacrylate (MMA) employing nickel acetylacetonate [Ni(acac)(2)] as catalyst combined with methylaluminoxane (MAO) as cocatalyst were investigated. The main purpose of this work is concerned with the study of reaction parameters MMA polymerization. Temperature of polymerization, Al/Ni mole ratio, type of solvent, catalyst concentration and time dependence were examined. The influence of Lewis bases on the polymerization was also studied. The binary system Ni(acac)(2)/MAO was the only one able to polymerize MMA at the conditions employed in this work. The cocatalytic activity of MAO was compared to those of common alkylaluminium compounds. The polymers were characterized by gel-permeation chromatography (GPC) and C-13-NMR techniques.