Microwave radiometric measurements in the 60-GHz oxygen band are considered to infer atmospheric wind fields associated with tropical storms. On the basis of the thermal wind equation the radial derivative of brightness temperature is related to the vertically weighted tangential wind through a wind weighting function. The theory is tested in an analysis of Nimbus 6 scanning microwave spectrometer (Scams) 55.45-GHz data through typhoon June in November 1975. Scams-derived winds are obtained for 3 days throughout the storm area and are compared with 700-mbar aircraft reconnaissance winds. Major differences with the reconnaissance winds occur primarily near the storm center presumably owing to Scams' insufficient horizontal resolution. Also discussed are the errors due to upper level wind contributions and instrumental noise.