The activity and the polymer microstructures obtained for polymerizations of four different conjugated dienes catalyzed by CpTiCl3-MAO have been closely compared for a broad temperature range (-45 to +70 degrees C). Apparent activation energies of 16.1 and 13.1 kcal/mol have been obtained for the poorly chemoselective butadiene and (E)-1,3-pentadiene polymerizations, while an apparent activation energy close to 8 kcal/mol has been obtained for the highly 1,2-syndiospecific polymerization of 4-methyl-1,3-pentadiene. As for (Z)-1,3-pentadiene polymerization, previous experimental evidences of two competing mechanisms have been confirmed. A molecular modeling analysis, comparing three possible polymerization mechanisms for the four considered dienes, contributes to rationalization of the available polymerization results.