The article deals with the problem of the origin of Decimus Haterius Agrippa, cos. AD 22, and his kinship with the emperor’s family. Usually scholars suppose that his mother was the daughter of Marcus Agrippa by his fi rst wife Caecilia Attica or by his second wife Marcella Maior. But these versions do not agree with Tacitus’ evidence about the relatives of Haterius Agrippa and cause many chronological problems. In this article the author suggests another version: Decimus Haterius’ mother was not the daughter of Marcus Agrippa but his sister Vipsania Polla. This theory does not entail any chronological problems concerning the age of mother of cos. 22 AD, solves the problem of the social inequality of Haterius’ parents and explains why Tacitus does know of kinship of Decimus Haterius with Germanicus, but not of his kinship with Drusus Minor.