In early spring 2008, 2009 and 2010 the mining bee Andrena nycthemera Imhoff was found during several field trips in the north of Belgium. Several nesting sites were found and visited several times during the flight period. In general only few nests were found at aggregations in sandy habitats and it seems the species occurs in low number, but can be found widespread. All the nesting locations from Belgium are listed and a distribution map is drawn. The species is expected to be found in the Netherlands the coming years. Some of the nesting locations are very close to the border. At last, the phenology of the species has been studied.