Vapor deposition processes for forming thin films comprising gold on a substrate in a reaction space are provided. The processes can be cyclical vapor deposition processes, such as atomic layer deposition (ALD) processes. The processes can include contacting the substrate with a gold precursor comprising at least one sulfur donor ligand and at least one alkyl ligand, and contacting the substrate with a second reactant comprising ozone. The deposited thin films comprising gold can be uniform, continuous, and conductive at very low thicknesses.