The invention relates to a gas discharge lamp, in particular for motor-vehicle headlights, which has a maintaining-arc vessel (10) consisting of glass or the like, having at least two electrodes (15, 16, 23) and provided with a lamp base (11) which can be inserted into a base holder and has the electric connections (20, 21). A ballast is arranged in the lamp base (11) and supplies the lamp with the required starting and maintaining-arc voltage. Housing the ballast in the lamp base (11) produces an on-board, compact gas discharge lamp with short high voltage leads, thereby keeping the starting voltage low.