Going to Paris at about twenty years of age, he later opened a school of anatomy there in the winter of 1766, the success of which excited the jealousy of the established teachers and professors, who tried to make him give up his lectures.

In 1784, Desault moved to the Hôtel-Dieu to participate in a major ancien régime experiments in surgical education.

The clinical school of surgery which he instituted at the Hôtel-Dieu attracted great numbers of students, not only from every part of France (Pierre Bouchet from Lyon for example) but also from other countries; and he frequently had an audience of about 100.

In 1791 he established a Journal de chirurgerie, edited by his pupils, which was a record of the most interesting cases that had occurred in his clinical school, with the remarks which he had made upon them in the course of his lectures.

After being twice examined, he was seized on 28 May 1793, in the midst of delivering a lecture, carried away from his surgical theatre, and committed to prison in the Luxembourg.