Poly(1-hexene) was obtained with rac-ethylenebis(1-eta5-indenyl)zirconocenium alkyl catalyst. The ratio of the total proton NMR intensity to the olefinic end group intensity corresponds to the GPC-determined number-average molecular weight. The chemical shift and intensity of the alpha-CH2 at 34.4 ppm in the C-13 NMR spectrum indicate a highly isotactic microstructure for the poly(hexene). The C-13 NMR spectra contain minor resonances due to a variety of 1,2-disubstituted and 1, 1,2-trisubstituted vinylene and vinylidene end groups.