Abstract ; Depth profiles of stable water isotopes in the soil provide important information on flow and transport processes in the subsurface. We sampled depth profiles of stable water isotopes (2H and 18O) in the pore waters on two occasions at 46 sites in the Attert catchment, Luxembourg and are partly located in mixed deciduous forest and partly on grassland. These sites correspond to the sensor cluster sites of the DFG research unit CAOS. Sampling took place once between February 2012 and October 2013 and once in June 2014. Sampling procedure: We took 1-3 soil cores of 8 cm diameter in close proximity with a percussion drill (Atlas Copco Cobra, Stockholm, Sweden) at each study site within a radius of 5 m from the soil moisture sensor profiles. We drilled as deep as possible and divided the extracted soil cores into subsamples of 5 to 10 cm length and sealed the material in air tight bags (Weber Packaging, Güglingen, Germany). The soil sample depths were corrected for compaction during the drilling pro-cess and are provided as the mean depth of 5 or 10 cm soil core subsamples. For isotope analyses of the pore water, we used the direct equilibration method (Wassenaar et al., 2008). Analyses were carried out at the Chair of Hydrology, University of Freiburg. We provide detailed information about the laboratory analyses in Sprenger et al. (2015) and Sprenger et al. (2016) and the data description associated with the data.