Provided is a wiring holding structure, wherein wiring for electrically connecting a vehicle body to the vehicle sliding door is held in the vehicle body. The wiring holding structure comprises a step member provided adjacent to the vehicle sliding door and a holding portion for holding the wiring. The step member is molded of plastic material. The holding portion is for holding the wiring. The holding portion comprises a first holding portion integrally molded onto the step member; and a second holding member that is fixed to face the first holding section. The second holding member holds the wiring together with the first holding portion. The number of components necessary for the wiring holding structure can thereby be reduced, and the size of the wiring holding structure is made more compact.