A medical laser light source system including an excitation laser light source apparatus that generates first excitation light having a wavelength greater than or equal to 1.5 m and less than or equal to 2.2 m and second excitation light having a wavelength greater than or equal to 1.5 m and less than or equal to 2.2 m and differing from the first excitation light with respect to at least one of oscillation energy intensity, oscillation pulse width, repeating frequency, and peak power; an optical fiber that is long-distance and propagates the first excitation light and the second excitation light generated by the excitation laser light source apparatus; and a laser device that generates laser light having a wavelength of at least 2.7 m and no greater than 3.2 m, using at least one of the first excitation light and the second excitation light emitted from the optical fiber.