A light-source device for an endoscope includes a housing, first and second lamps, and first and second movable lamp mounting sections. The first movable lamp-mounting section is transferable with respect to the housing between first and second lamp positions. The second movable lamp-mounting section is attached to the first movable lamp-mounting section and is transferable between a lighting position and a lamp replacing position. The first lamp is optically connected to a light guide cable when the second movable lamp-mounting section is positioned at the lighting position and when the first movable lamp-mounting section is positioned at the first lamp position. The second lamp is optically connected to the light guide cable when the second movable lamp-mounting section is positioned at the lighting position and when the first movable lamp-mounting section is positioned at the second lamp position.