Disclosed is a process for phosphating a galvanized surface, particularly of galvanized steel wherein the surface is contacted for up to 10 seconds with a phosphating solution which contains accelerator, particularly nitrate,0.5 to 5.0 g/l zinc,3 to 20 g/l phosphate (calculated as P.sub.2 O.sub.5),0.3 to 3 g/l magnesiumat a weight ratio of magnesium: zinc=(0.5 to 10):1 and has an S value in the range from 0.2 to 0.4 preferably in the range from 0.2 to 0.3, and is replenished with a concentrate in which the weight ratio of zinc to phosphate (calculated as P.sub.2 O.sub.5) is in the range from (0 to 1):8.It is particularly desirable to use a phosphating solution which contains up to 1.5 g/l zinc, preferably 0.5 to 1 g/l zinc, at a weight ratio of magnesium: zinc of (0.5 to 3:1, nickel ions in an amount of up to 1.5 g/l, preferably in an amount of up to 0.5 g/l and simple or complex fluoride in an amount of up to 3 g/l, preferable 0.1 to 1.5 g/l (calculated as F in each case).A special advantage is afforded by the use of the process to treat galvanized steel strip which is subsequently painted or coated with a preformed organic film.