Measurements of the differential Doppler shift between various points on Venus using a high-resolution PEPSIOS interferometer. Using both a CO2 line and a Fraunhofer line a mean zonal-wind velocity of about -83 m/s is found near the equator; the velocity appears to vary from about -2 to -125 m/s with a time scale of greater than one week. Meridional velocities are measured to be weak. The equatorial zonal velocity appears to be smaller in the 'morning' than in the 'afternoon'. A comparison with reported velocities of the ultraviolet dark markings reveals general agreement in that both find the motion to be retrograde, variable, and accelerated during the day. A new potential source of systematic error in all spectroscopic determinations of the differential Doppler shift of nonuniformly illuminated objects is pointed out.