Ocean tides are an important phenomenon that has to be considered in a variety of geoscientific investigations in polar regions. Using ocean tide models, appropriate corrections can be calculated and applied in the different analyses, e.g. to infer temporal mass variations from satellite data, to investigate ice-shelf dynamics and deformation, to come up with precise station positions and velocities within a terrestrial reference system. However, those models show larger uncertainties in the polar seas and at areas covered by ice shelves and, therefore, need to be improved. Within this context, tidal gravimetry provides a powerful tool to validate ocean tide models. Sensing the cumulative signal of different effects (solid earth tides, ocean tidal loading, atmospheric loading) tidal gravimetry can be regarded as an independent observation technique and thus complements continuous GPS measurements. This paper reviews the background and the work done so far by the authors in Greenland and in Antarctica. Within a current project tidal gravimetry is applied at the Argentine Antarctic stations Belgrano II and San Martín. This joint Argentine-German project is a contribution to the IPY project POLENET. The set-up of the instruments in Belgrano II as well as first results of the ongoing observations, started February 2007, are presented. We discuss the problem of observing ocean tides in the area of the glacier near Belgrano II, which is – at least in parts – freely floating.