Propene was polymerized with methylaluminoxane (MAO) and cationic activated rac-dimethylsilylene-2-methylbenz[e]indenylzirconocene [MBI-Cl-2] and [MBI-Me-2]. For cationic activation of the MBI-Me-2 system tris(pentafluorophenyl)borane [I], N,N-dimethylanilinium tetra(pentafluorophenyl)borate [II] or trityl tetra(pentafluorophenyl)borate [III] were used. The MAO-activated dimethyl complex showed higher activity with respect to the dichloride system using high catalyst concentrations and [Al]/[Zr] ratios. Most effective cationic activator for MBI-Me-2 was N,N-dimethylanilinium tetra(pentafluorophenyl)borate [II] in combination with Al(i-Bu-3). Using tris(pentafluorophenyl)borane III at different polymerization conditions or N,N-dimethylanilinium tetra(pentafluorophenyl)borate [II] in combination with Al(Et)(3) no propene polymerization was observed due to the occurrence of reduction of the catalytically active site.