A detailed geophysical survey has been carried out on the side of the Iron Age hill fort at Châtillon-sur-Glâne, Fribourg, Switzerland, with the aim of locating the zone of archaeological occupation. The electrical resistivity measurements, which were carried out using a twin electrode array, reveal resistivity variations which are due to heterogeneities in the fluvioglacial soil, probably of geological origin. However, the magnetic methods are more successful. The magnetic susceptibility of the topsoil is significantly higher towards the NW ramparts as well as to the centre of the site, and these magnetically enhanced areas are interpreted as the probable occupation zones. The vertical magnetic field survey, although disturbed in the northern part by modern iron scrap left by previous excavations and tourists, reveals features which could be of archaeological interest (e.g. hearths). The conclusions of the geophysical survey are in broad agreement with the findings of several test pits dug on the site.