Carbon disulfide (CS2) was determined in surface waters of the North Atlantic and Pacific Oceans. The mean concentrations (and ranges) of CS2 in open ocean waters were 13.4(7.8--26.1)pM S (picomol sulfur per liter) for the North Atlantic and 14.6(7.2--27.5)pM S for the Pacific. The concentrations in the coastal waters of the North Atlantic averaged 26.4pM S and ranged from 17.9 to 40.4pM S. Warm waters generally contained higher levels of CS2 than did cold waters. All the study areas were found to be supersaturated in CS2 relative to the atmosphere based on calculations from published CS2 mixing ratios in the marine boundary layer and their Henry's law constants. Sea-to-air fluxes of CS2 were estimated using exchange velocities for spot and climatological wind speeds. The global oceanic flux extrapolated from this study is 0.18 Tg CS2 yr-1 and in the range 0.13--0.24 Tg CS2 yr-1. It is suggested that microbial processes, photochemical reactions, and phytoplankton activity are potential sources for oceanic CS2. ¿ 1999 American Geophysical Union