A fuel tank and radiator layout structure for a saddle type vehicle that makes the vehicle smaller-sized and compact while securing cooling efficiency of a radiator. A front wall of a fuel tank is inclined forward to obliquely extend downwardly rearward from its upper end. The radiator is disposed on the rear and lower side of the front end of the fuel tank, and the radiator is provided vertically or is inclined forward so as to have its lower end located rearwardly of its upper end in side view. The forward inclination angle of the front wall of the fuel tank relative to the vertical is greater than the forward inclination angle of the radiator relative to the vertical.