The series of (1-terpenylindenyl)(2)ZrCl2 bent metallocene complexes (with terpenyl substituents neomenthyl, neoisomenthyl, menthyl, and isomenthyl) were obtained from the reaction of the respective 1-terpenylindenyl lithium reagents with ZrCl4. In each case a single racem-like diastereoisomer was isolated pure by crystallization. The conformational analysis of the bent metallocene systems was carried out by variable temperature H-1 NMR spectroscopy. It has revealed the existence and equilibration of three different bent metallocene torsional isomers. Two of these are C-2-symmetric and carry their bulky terpenyl substituents either in the lateral or the front sector of the bent metallocene wedge (descriptors bis-lateral:anti (conformer A) and bis-central:syn (conformer B)), whereas the rotational isomer C (central, lateral:gauche) is of lower symmetry. The (1-terpenylindenyl)(2)ZrCl2/methylalumoxane systems are active propene polymerization catalysts. The equilibrium amount of the "stereochemically productive" C-2-symmetric bis-lateral:anti bent metallocene conformer A correlates qualitatively with the observed isotacticity of the propene polymerization process at the respective group 4 bent metallocene catalyst system.