Following the death of his uncle Prince Adolf II in a plane crash in 1936, Philipp-Ernst's father Wolrad became the new head of the House of Schaumburg-Lippe.
After his older brother, Hereditary Prince Georg-Wilhelm, was killed in action at Nössige, Saxony, on 29 April 1945 during the second world war, Philipp-Ernst became the new heir apparent to the House of Schaumburg-Lippe.
Philipp-Ernst succeeded to the headship of the house on the death of his father on 15 June 1962, and he remained head until his death at Bückeburg, when he was succeeded by his only surviving son, Alexander.
He was married to Eva-Benita Freiin von Tiele-Winckler (1927–2013) at Bückeburg on 3 October 1955.
They had two sons, with the elder Georg-Wilhelm dying in a motorcycle accident in 1983.