A light source device for endoscopes includes a light source for emitting white light containing the components of light belonging to a visible region and wavelength bands other than the visible region; at least, a rotary color separating filter on a field sequential system; and an infrared cutoff filter for blocking light in an infrared region, of a wavelength band of the white light. When the rotary color separating filter is disposed in an optical path from the light source to a light guide, an interference filter in which an interference film is applied to a transparent base plate is placed in the optical path. This arrangement obviates the defect of burning the entrance end of the light guide or of breaking the infrared cutoff filter.