A method of controlling run-up of a metal halide lamp that has a nominal (full) light output during steady state operation and that has a current limit I.sub.lim, includes, during run-up of the metal halide lamp to steady state operation, evaluating requested power P.sub.req and requested current I.sub.req to operate the lamp at the nominal light output L.sub.n during the run-up, supplying I.sub.lim to operate the lamp so long as I.sub.req.gtoreq.I.sub.lim and supplying P.sub.req to operate the lamp when I.sub.req