With six different metallocenes, namely Pr-i[CpFlu]ZrCl2 I, Pr-i[3-MeCpFlu]ZrCl2 II, Pr-i[3-EtCpFlu]ZrCl2 III, Pr-i[3-(i)PrCpFlu]ZrCl2 IV, Pr-i[IndFlu]ZrCl2 V and Pr-i[3-(t)BuCpFlu]ZrCl2 VI propene polymerizations were carried out at different polymerization temperatures. MAO was used as a cocatalyst for all polymerizations. In case of metallocenes II, Ill and TV an increase in isotacticity with increasing polymerization temperature was observed. This is due to the increased rotation and, as a consequence, to the increased steric demand of the substituent at the cyclopentadienyl residue. With metallocene V a catalyst of in principle the same type was synthesized, but rotation of the substituent is not possible. Here, in the contrary, the assumed effect was observed, that the stereospecificity of the metallocene decreases, while raising the polymerization temperature. In metallocene I there is no rotatory substituent at the cyclopentadienyl residue and therefore a more stereoirregular polymer is formed at higher polymerization temperatures. Metallocene VI produces poly(propylene) with slightly increased isotacticity at higher polymerization temperature.