He grew up with his two brothers, Axel Nielsen (1902–1970) and Povl Erik Nielsen (1909–1995) in Glostrup, 10 kilometres west of Copenhagen.
Nielsen ratings | Leslie Nielsen | John Marius Wilson | Nielsen SoundScan | Nielsen Media Research | Brigitte Nielsen | Nielsen | Gaius Marius | Beth Nielsen Chapman | Marius Petipa | Asta Nielsen | Teresa Nielsen Hayden | Marius Neset | Holger Drachmann | Holger Czukay | Nielsen Broadcast Data Systems | Kay Nielsen | Holger Klose | Marius von Mayenburg | Marius Eriksen, Jr. | Marius Eriksen | Marius de Romanus | Marius Constant | Marius Canard | Marius | Juanita Nielsen | Jim Nielsen | Jerri Nielsen | Jakob Nielsen (usability consultant) | Jakob Nielsen |