The presence of habitats such as burrows and dense willows along the rivers is very important for the survival of the European otter in terms of structures allowing quiet living conditions and possibilities for reproduction. To prevent the extinction of the otter in Luxembourg and nearby areas, an assessment of otter habitats and populations was made in 1994. This first evaluation has demonstrated that only rivers in the north of Luxembourg were suitable for otter populations in terms of quality of habitats and that only a few individuals were still present in this part of the country. In 2007, a new habitat assessment was carried out to define priorities for the management of habitats and to build or rebuild corridors to support otter migration and allow re-establishment of stable otter populations in the Benelux Countries. Two similar methods were used to assess quality of habitats in 1994 and 2007. The results of the habitat assessment are different for the Mid Sûre River and similar for the River Wiltz, the River Wark, the River Our and the Upper Sûre River. This variation is probably due to assessment complexity and observer subjectivity, but also to the difficulty to have a practical methodology for management priorities. From this point of view it would be useful to have a standard methodology at the European level to assess otter habitats.