Eight different solvents, of different polarities, were used to prepare carbon nanofiber (CNF)/poly(methyl methacrylate nanocomposites by solvent casting. Selected solvents ranged from organic acetone to nonpolar toluene, passing through N-containing solvents. In addition, pristine and oxygen and nitrogen-functionalized CNFs were used. Two objectives were pursued: (1) the role of the solvent in the dispersion of the CNFs and (2) the benefit of the functionalization on the dispersion through the stability in the solvent and compatibility with the matrix. The dispersion analysis of the materials leads to the conclusion that solvents containing oxygen groups work better with the oxidized CNFs, similarly solvents containing nitrogen groups with the nitrogen-functionalized CNFs. (C) 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012