Maizière took part in the Invasion of Poland and Eastern Front, as an aide to General Adolf Heusinger.

Upon the surrender of Germany, he went into British captivity and lived as a civilian from his release to 1955, when he joined the German Army of the new Bundeswehr and worked in the Federal Ministry of Defence (Colonel).

In 1967 Maizière formally congratulated Field Marshal Erich von Manstein at his 80th birthday.

During his retirement he wrote the books: Führen im Frieden - 20 Jahre Dienst für Bundeswehr und Staat ("Leading in Freedom: 20 Years Served for Federal Defence and State")(1974) and In der Pflicht - Lebensbericht eines deutschen Soldaten im 20.

His brother Clemens de Maizière decided to stay in the Soviet-occupied part of Germany and became one of the founding members of the CDU (Ost), his nephew Lothar de Maizière was the last Prime Minister of the German Democratic Republic (East Germany), while his son Thomas de Maizière served as Federal Minister of Defence as well as Federal Minister of the Interior.