The homoleptic scorpionate sandwich complex [(TpPh,Me)2Ni] (1), where TpPh,Me = hydrotris(3-phenyl-5-methylpyrazol-1-yl)borate, crystallizes as a mixture of two polymorphs. A major monoclinic fraction crystallizes as well-formed parallelepipeds and a minor triclinic fraction forms irregularly shaped, anhedral crystals. These exhibit distinct melting points (288 and 294 °C, respectively) as observed by differential scanning calorimetry. We obtained X-ray crystal structures of both polymorphs at 100 K. The complex adopts different conformations between the two lattices. These are supported by distinctive ensembles of intramolecular non-covalent interactions, specifically π-stacking and perpendicular C–H···π contacts between opposing 3-phenylpyrazolyl arms on the co-ligands. The conformation found in the major monoclinic polymorph consists of a counter-rotation of the ligands that reduces the ideal complex symmetry from D3d to D3 and results in three-fold pair-wise association of 3-phenylpyrazolyl arms. In contrast, an alternate conformation of 1 in the minor triclinic polymorph consists of two triads, with an ideal complex symmetry of C2h. Also affected are the tetragonality of the ligand fields and interligand N–Ni–N′ bond angles. A review of sandwich complex structures [(TpR)2M], where R is an aromatic substituent, shows these conformations are adopted broadly. Hence, substituent effects in second-generation scorpionate ligands are not merely steric in origin.