Dimethylsulfide (DMS) concentrations were measured in ocean waters, along the West Coast of the United States on three cruises during 1983 and 1984. Concentrations in surface waters ranged from 13 to 380 ng S/L with a summer average of 60 and a winter average of 20 ng S/L. The flux of sulfur from the ocean to the atmosphere was calculated using the stagnant film boundary layer model to be 28 mg S/m2/a. On the basis of a non-sea salt sulfate residence time of 5 days, the calculated net flux of biogenic sulfur to the West Coast of the United States is 0.045 Tg/a. This is 4-13% of the combined total anthropogenic emissions from the western United States.