Oceanic whitecaps may exert a cooling influence on the planet by increasing surface albedo. The direct, globally averaged radiative forcing due to whitecaps lies in the range 0--0.14 Wm-2 with a probable value of 0.03 Wm-2. Though small, this global value is not negligible compared with the forcing due to some greenhouse gases and anthropogenic aerosols since preindustrial times. The relative importance of whitecaps may be greater on regional and seasonal scales, with radiative forcing values reaching 0.7 Wm-2 in the Indian Ocean during summer. Whitecap effects on surface albedo should be taken into account explicitly in the numerical modeling and analysis of climate change. ¿ 2001 American Geophysical Union