Styrene was polymerized using combined systems of diphenylzinc, Ph(2)Zn, and metallocene compounds activated by methylaluminoxane, MAO. From the various employed bis(indenyl)zirconium dichloride, Ind(2)ZrCl(2), [isopropyl(cyclopentadienyl)(1-fluorenyl)] zirconium dichloride, i-Pr(Flu)(Cp)ZrCl2, and bis(cyclopentadienyl) titanium dichloride, Cp(2)TiCl(2), produced the larger amounts of polymer. Ph(2)Zn-Cp(2)TiCl(2) - MAO system gave polystyrene, PSt, whose DSC analysis indicated a major endotherm peak at 256 degrees C. A butanone insoluble fraction of the polymer was separated from the crude PSt. The proportion of insoluble polymer depends on the metallocene employed and on the conversion to polymer.