The molecular weight (MW) and the molecular weight distribution (MWD) of polyethylene (PE) prepared with various metallocene catalysts were investigated. The weight-average molecular weight ((M) over bar(w)) of PE prepared with dicyclopentadienyltitanium dichloride/ aluminoxane (Cp(2)TiCl(2)/MAO) was about 4,0 . 10(5), while that of PE obtained with dicyclopentadienylzirconium dichloride/aluminoxane (Cp(2)ZrCl(2)/MAO) is about 1,0 . 10(5). PE of bimodal MWD was obtained with the mixed catalyst Cp(2)TiCl(2)/Cp(2)ZrCl(2). Narrow MWD PE was obtained with the mixed catalyst Cp(2)Zr(C)1(2)/Et(ind)(2)ZrCl2, because each catalyst produced an (M) over bar(w) of 1,0 . 10(5). However, the change of temperature during the polymerization with the mixture Cp(2)ZrCl(2)/Et(ind)(2)ZrCl2 produced PE with a bimodal MWD and a value of the ratio of weight- to number-average molecular weights of (M) over bar(w)/(M) over bar(n) = 4.