New Au(I) complexes featuring ligands of the type kappa(1)-3-R2P-indene (kappa(1)-1a, R = Pr-i; kappa(1)-1b, R = Ph) and kappa(1)-1-R2P-2-Me2N-indene (kappa(1)-1c, R = Pr-i; kappa(1)-1d, R = Ph) were prepared and structurally characterized. Dicoordinate neutral complexes (kappa(1)-1)AuCl (2-5) were prepared by reacting 1 with Me2SAuCl, with isolated yields ranging from 56 to 88%. Addition of a second equivalent of 1a to 2 resulted in formation of the tricoordinate neutral species (kappa(1)-1a)(2)AuCl (6; 69%). By treating 6 with AgOTf, the corresponding cationic complex [(kappa(1)-1a)(2)Au]+OTf- ([7]+OTf-; 72%) was obtained. The catalytic performance of these new Au(I) compounds in the hydrosilylation of various aldehydes was compared to that of catalyst systems derived from a combination of R3P (R = Et, Bu-n, Bu-t, Cy, or Ph) or N-heterocyclic carbene ligands and Me2SAuCl. While for the phosphine-substituted indene complexes, a catalyst mixture of 3 mol % 2 and 20 mol % 1a was found to be optimal, a catalyst derived from 3 mol % Me2SAuCl and 20 mol % Et3P, (Bu3P)-Bu-n, or (Bu3P)-Bu-t proved to be the most effective overall, especially for reactions conducted at 24 degrees C. Single-crystal X-ray diffraction data are provided for 2, 4, 6, and [7]+OTf-.