A method for managing a gas discharge lamp in particular for a motor vehicle headlamp. The method is of the type which consists in controlling initial and nominal supply powers of the lamp by means of control signals during the operating phases of the lamp which comprise a start-up phase, an ignition phase and a steady-state phase. The method is wherein the control signals comprise command signals which are generated externally of the ballast and which force each of the supply powers to a value selected from a set of predetermined powers as a function of each of the phases. The method makes it possible for example to manage the different modes defined by the new regulations of the AFS type, and to optimize the service life of the lamp.