The capabilities of the Global Positioning System (GPS) for accurately determining geodetic quantities are well established. Nevertheless, no comparison between deflections of the vertical as determined through GPS with leveling and values conventionally computed by astrogeodetic methods has yet been published. This investigation demonstrates that accurate deflections of the vertical components (&eegr;, &xgr;) can be obtained independently of classical astronomic observations by combining geodetic leveling with satellite GPS positioning. The approach uses a radial configuration of baselines to determine the ''best'' (in a least squares sense) values of (&eegr;, &xgr;) at the central station.