The effect of ascorbic acid on the response of several metals in sea water obtained by graphite-furnace atomic absorption spectrometry was evaluated from the variation of peak time and the sensitivity. Matrix interferences from sea water in the determination of lead, manganese, vanadium and molybdenum were suppressed by addition of 10% (w/v) ascorbic acid solution to the sample in the furnace. Matrix effects on the determination of cobalt and copper could not be removed in this way. A direct method for the determination of lead, manganese, vanadium and molybdenum in sea water is proposed.