An autofluorescence endoscope system including first and second exciting light sources, an exciting-light cut-off filter, an imaging device, a light-source controller, and an imaging device driver, is provided. The first and second exciting light sources emit first and second exciting light, respectively. The wavelengths of the first and second exciting lights range in a first and second band, respectively. The first and second exciting lights make an organ autofluoresce. The wavelength in the second band is longer than that of the first band. The exciting-light cut-off filter attenuates a light component at least of the first or second band from an optical image. The imaging device captures an optical image of the subject passing the exciting-light cut-off filter. The light-source controller controls the first and second exciting light sources.