In August 1993, a 915-MHz boundary layer wind-profiling radar was deployed at Chebogue Point, Nova Scotia, to provide wind, turbulence, and boundary layer structure information for the North Atlantic Regional Experiment summer 1993 intensive campaign. The National Research Council Canada Twin Otter atmospheric research aircraft was also part of that campaign. During the campaign, the Twin Otter flew 29 soundings over Chebogue Point. This paper describes a comparison of the wind speed and direction measured by the profiler and the aircraft. In the height range 300–2000 m above sea level, the random difference between the wind speed measurements is 0.9 m s−1, and the random difference between the wind direction measurements is 9°. There is a small systematic difference in the wind speeds (0.14 m s−1) that is probably due to uncertainty in the zenith angles of the radar beams and extremely good agreement (within 0.5°) in the wind direction. The Kalman filter-smoother technique used to remove drifts in the inertial navigation system is shown to be important in achieving these favorable results.