A method has been developed to estimate daily surface fluxes of momentum and sensible and latent heat over the global oceans using a stability-dependent bulk scheme. Daily fluxes are computed from daily values of special sensor microwave imager (SSM/I) surface winds, SSM/I surface humidity, National Centers for Environmental Prediction sea surface temperatures (SSTs), and European Centre for Medium-Range Weather Forecasts (SSTs minus 2-m temperatures). Daily surface specific humidity is estimated from the SSM/I water vapor for an atmospheric column and the lower 500 m of the planetary boundary layer, using the method of Chou et al. <1995> with two modifications for the extratropical oceans. The modified method is described using two simple equations. Gustiness parameterization for the weak winds and convective situations is found to have an insignificant impact on the air-sea fluxes derived from the SSM/I data and hence is not included. The SSM/I-radiosonde comparison (over the global oceans for the entire annual cycle of 1993) shows that for a 25-km resolution the instantaneous SSM/I surface humidity has a root-mean-square (rms) difference of 1.83 g kg-1. Daily SSM/I latent heat fluxes (and wind stresses) agree well with the flux measurements over the western Pacific warm pool, with a bias of 6.2 W m-2 (0.0061 N m-2), an rms difference of 29.0 W m-2 (0.0187 N m-2), and a correlation of 0.83 (0.86). Monthly results of February and August 1993 show that the patterns and seasonal variabilities of the SSM/I surface humidity, latent, and sensible heat fluxes are generally in good agreement with those of the Comprehensive Ocean-Atmosphere Data Set (COADS) and climatologies derived from ship measurements. The SSM/I sensible heat flux is generally within ¿10 W m-2 of COADS. However, the SSM/I latent heat flux is generally larger, especially over the wintertime trade wind belts. The result is consistent with previous climatological studies in that the latent heat fluxes based on ship measurements are systematically underestimated.¿ 1997 American Geophysical Union