After studying in Bordeaux, he was the first Sephardic pupil admitted to the rabbinical school in Metz.
In June 1866, he was appointed as the Chief Rabbi of Belgium, yet he retained his French nationality.
In 1871 General Emile Mellinet commissioned Edgar Degas to paint a double portrait of himself and Rabbi Astruc to celebrate their service together in the ambulance corps during the Franco-Prussian War.
He died on February 23, 1905, in Brussels, Belgium and is buried in the Jewish cemetery in Uccle.
Astruc also called for a rational explanation of the Bible, questioning its dogmatic manifestation in the Western world.