Disclosed is a vehicle wiring structure that uses a power cable to connect a power source and an electrical load disposed, inside a vehicle, with a space therebetween in the vehicle front-to-back direction. The vehicle wiring structure is provided with a metal pipe (20) which is disposed on vehicle floor under surface (61), between a position below where the power source is installed and a position below where the electrical load is installed, and two ends of which are inserted into the vehicle, and a power cable that is inserted through the metal pipe (20) and connects the power source and the electrical load. The metal pipe (20) is provided slanting from the two ends toward a bottommost part (21), in the vertical direction, and the bottommost part (21) is heated by heat released from CAT (51).