This paper presents results of a study carried out in order to assess the applicability of32Si for groundwater dating. Measurements of32Si in soil samples of the unsaturated zone, of drainage waters and plant material give a basis for estimating the32Si initial concentration in groundwater. Different aquifers with groundwater of young and moderate ages have been selected for groundwater studies. For obtaining independent age information tritium was found to be a suitable reference isotope. A quantitative interpretation of the32Si data is generally complicated by geochemical processes, preferably in the unsaturated zone. Favourable conditions concerning the use of32Si in hydrogeology seem to exist in phreatic sandy aquifers, in limestone aquifers, and, depending on the thickness and composition of the unsaturated zone, in sandstone aquifers. Further improvements of the32Si method needs a better understanding of the geochemical processes affecting this isotope.