SEASAT carried three wind speed microwave sensors: a scatterometer (SASS), an altimeter (ALT), and a five-frequency radiometer (SMMR). The winds inferred by these sensors along with colocated in situ comparisons show an agreement of about 2 m/s. A larger statistical data base is obtained by intercomparing the three sensors in the absence of in situ data. For nadir observations at wind speed below 10 m/s, the three instruments track each other very well and seem responsive to wind as low as 2 m/s. However, for winds above 10 m/s the ALT winds are biased low relative to the SASS and SMMR winds. The discrepancy at high wind speeds between the SASS and ALT is due to using different model functions in the geophysical processing. When properly filtered for land, sun glitter, and rain, the SASS and SMMR winds agree remarkably well. For 329 SASS and SMMR comparisons over a wind speed range from 2 to 20 m/s, the mean difference is 0.03 m/s, the standard deviation is 1.42 m/s, and the correlation is 0.95. The ability of the SMMR to measure wind speed is adversely affected by proximity to land and sun glitter. The SMMR cell must be at least 600 to 700 km from land, and the sun angle must be greater than 20¿ to ensure accurate winds. Both SASS and SMRR retrieve wind speeds near the eye of Hurricane Fico that are in good agreement with each other and with surface observations. Light rain of about 2 mm/h does not appear to seriously degrade the performance of the SASS or SMMR.