A dishwasher for treating dishes includes a tub at least partially defining a treating chamber, a spraying system having a distribution header and at least one aperture provided on the distribution header for spraying wash liquid into the treating chamber, and a recirculation system for recirculating liquid sprayed in the treating chamber to the spraying system. A light assembly is provided on the distribution header, and includes a light source that emits light to a light guide, which in turn distributes light to the treating chamber.