He was born and died in Dessau, and was the third and youngest son of John V, Prince of Anhalt-Zerbst by his wife Margaret, daughter of Joachim I Nestor, Elector of Brandenburg.
Bernhard inherited Anhalt-Zerbst when his father died in 1551 along with his older brothers Karl I and Joachim Ernest according to the stipulations of the family law of the House of Ascania, which mandated no division of the territories of the principality.
In 1562 Anhalt-Köthen was also merged into Anhalt-Zerbst after the death without issue of its last prince, Wolfgang.
In Dessau on 28 May 1565 Bernhard married Clara (b. Gifhorn, 1 January 1550 – d. Franzburg, 26 January 1598), posthumous daughter of Francis, Duke of Gifhorn.
They had only one son: Bernhard died without surviving male heirs and was succeeded by his brother Joachim Ernest, who became sole ruler of all the Anhalt territories.