Abstract: An illuminated spirit level containing fiber optic cables for the transmission of light from the self contained light source to the level vials is disclosed. The lighting system provides for several improvements over other such devices, including a light chamber with a highly reflective interior for containment of the light source and fiber optic cable ends, and opposite cable ends formed to closely fit the contours of the level vials for greater light transmission efficiency. Provision is made for recharging the batteries, and inadvertent actuation of the system may be prevented by locating the switch within an aperture contained within the level frame, a momentary on or pushbutton type switch, and/or the inclusion of a delay circuit providing automatic deactivation of the circuit when a predetermined time has elapsed after activation. The electrical components may be secured within the level by cover plates, which also provide secure storage for a spare electrical bulb.