A series of C-1 symmetric, 1,2'-bridged bis(indenyl)zirconium dichlorides were prepared to study the effect of ligand substitution, symmetry, and bridge identity on the stereoselectivity of propylene polymerization. Unsubstituted [1-(1-indenyl)-2-(2-indenyl)ethane] zirconium dichloride, Et(2-Ind)(1-Ind)-ZrCl2 (1), was synthesized, and its propylene polymerization behavior was compared to three 2-phenyl-substituted complexes with different bridges: [2-(2-indenyl)-1-(2-phenyl-1-indenyl)ethane] zirconium dichloride, Et(2-Ind)(2-Ph-1-Ind)ZrCl2 (2), [(2-indenyl)-(2-phenyl-1-indenyl)dimethylsilyl] zirconium dichloride, Me2Si(2-Ind)(2-Ph-1-Ind)ZrCl2 (3), and [(2-indenyl)-(2-phenyl- 1-indenyl)methane] zirconium dichloride, CH2(2-Ind)(2-Ph-1-Ind)ZrCl2 (4). The polymerization activity, polypropylene molecular weight, and microstructure were dependent upon the identity of the bridge and the substitution patterns on the metallocenes. Metallocenes 1, 2, 3, and 4 are characterized by a gauche orientation of the indenyl ligands, in contrast to the anti or syn orientation of 1,1'-bridged ansa-bis(indenyl)metallocenes. The gauche metallocene 3 yields a polypropylene of intermediate isotacticity ([mmmm] = 58%) when compared to the C-2 symmetric anti-Me2Si(2-phenyl- 1-indenyl)(2)ZrCl2 ([mmmm] = 86%) and the C-8 symmetric syn-Me2Si(2-phenyl-1-indenyl)2ZrCl2 ([mmmm] = 7%). The gauche metallocene 2 yielded the most highly isotactic polypropylene ([mmmm] = 74%). Analysis of the sequence distributions of the polypropylenes derived from metallocenes 1-4 reveals a predominance of [mrrm] stereoerrors. The high stereoselectivity of the bridged metallocenes 1-4 implies that gauche conformations may be responsible for some of the higher tacticity fractions observed in polypropylenes derived from the unbridged 2-arylindene metallocenes.