Presented at the 2013 Aquarius/SAC-D Science Team MeetingIn this work we present the wind speed retrieval obtained using MWR instrument data. The retrieval model was developed jointly between CONAE and CFRSL, and is actually used to generate Wind Speed L2 product distributed by CONAE and PODAAC. The model is based on the microwave radiative transfer theory developed by Remote Sensing System (Wentz et al). It uses MWR brightness temperature at 36.5 GHz in both horizontal and vertical polarizations and auxiliary data (such as sea surface temperature obtained from GDAS, wind direction from NCEP, etc). As a result, the neutral stability ocean surface wind speed at 10 m height and the atmospheric transmissivity at 36.5 GHz are retrieved. We also show typical results for a pass and global wind speed averages in different seasons. In addition, we present validation results using Windsat data for comparisons, based on statistical procedures.