Particulate and vapor phase selenium sampling was conducted in urban and coastal Rhode Island, at a coastal site in American Samoa, aboard ship in an upwelling area near the Peru coast, and at two sites in the Hawaiian Islands as part of the SEAREX program. Approximately 25% of the atmospheric selenium was found in the vapor phase at all locations with the exception of Peru, where ~10% of the total selenium was in the vapor phase, and above the marine boundary layer in Hawaii, where ~45% of the selenium was in the vapor phase. Vapor phase selenium appears to be produced naturally as well as anthropogenically. An examination of representative worldwide particulate selenium concentrations reveals the remarkably uniform distribution of atmospheric selenium. Concentrations decrease by only about a factor of 100 from urban to remote marine and continental locations. This may be due to the uniform nature of one important vapor phase source of selenium, the ocean. Vapor to particle conversion of this naturally produced oceanic selenium may explain most of the particulate selenium enrichmnent observed in remote marine areas.