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 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

Prince Amedeo Marie Joseph Carl Pierre Philippe Paola Marcus d’Aviano, Archduke of Austria (born 21 February 1986); married Elisabetta Maria Rosboch von Wolkenstein (b. 1987) on 5 July 2014. The couple have one daughter:
Archduchess Anna Astrid of Austria-Este (born on 17 May 2016) (age 4 months 5 days)
Princess Maria Laura Zita Beatrix Gerhard, Archduchess of Austria-Este (born 26 August 1988)
Prince Joachim Karl-Maria Nikolaus Isabelle Marcus d’Aviano, Archduke of Austria-Este (9 December 1991)
Princess Luisa Maria Anna Martine Pilar, Archduchess of Austria-Este (born 11 October 1995)
Princess Laetitia Maria Nora Anna Joachim Zita, Archduchess of Austria-Este (born 23 April 2003)
Astrid is also godmother to Archduchess Marie-Christine of Austria, Prince Sébastien of Luxembourg and Prince Gaston of Orléans