Results of geoelectrical resistivity monitoring at two landfill sites, a bioreactor landfill and a conventional municipal solid waste landfill site over a week are reported. The main objective was to investigate if geoelectrical resistivity can be used for localising paths for landfill gas migration. The resistivity results were also related to local pore pressure measurements and to methane emission measurements using a laser-scanning instrument. The results suggest that the use of the interpreted resistivity and of its temporal variation can be suitable for the intended purpose, and confirm the applicability of resistivity imaging at landfills. It is also concluded that better knowledge about the dependence of resistivity variation to temperature, porosity and moisture content variations would improve the interpretation and that measuring or monitoring at least one of these additional parameters together with resistivity would be useful.