This Letter reports an alternate route for judging optimized processing conditions during the preparation of conductive polypropylene/carbon nanotubes composites by melt-mixing. The control of the nanotubes dispersion is performed indirectly through both the dc conductivity and the crystallization temperature values of the nanocomposites. Comparison of the obtained findings with both scanning electron microscopy and optical light microscopy results reveals that this indirect route is easier, faster and sometimes more precise for the optimization of the preparation conditions, compared to commonly applied microscopy techniques. The proposed methods are expected to have a more general impact, being applicable to other polymer nanocomposites. (C) 2010 Elsevier B.V. All rights reserved.