Princess Astrid married Archduke Lorenz of Austria-Este, the head of the Archducal House of Austria-Este, on 22 September 1984 at Brussels.[ Lorenz is the eldest son of the late Robert, Archduke of Austria-Este (1915–1996), and his wife Princess Margherita of Savoy-Aosta (born in 1930). Her husband was also created Prince of Belgium by Royal Decree on 27 November 1995.

Princess Astrid and Prince Lorenz have five children, who bear the title "Prince/Princess of Belgium" (in each of the three official languages) as members of the Belgian royal family and Archduke/Archduchess of Austria