Pierre Joseph, a distinguished French surgeon, was born at Magny-Vernais, a village of Franche-Comté, in 1744. He was descended of humble parents; received the early part of his education in a school of the Jesuits, and was destined for the church; but his own inclination tended to the study of medicine; and he was at length settled as an apprentice in the military hospital of Béfroi. Here he acquired some knowledge of anatomy and surgery; and having previously made considerable progress in mathematical studies, he applied this knowledge, after the example of Borelli and others, to the investigation of physiological subjects. He early translated the work of Borelli De motu Animalium, and added notes and illustrations, which, although founded on wrong principles, gave undeniable proofs of zeal and industry.

He went to Paris when about twenty years of age, and opened a school of anatomy in the winter of 1766, which was soon attended by about three hundred pupils, a great proportion of whom were older than himself. His success excited the jealousy of the established teachers and professors, who exerted all the influence of authority to silence him; and although he was patronized and protected by some surgeons of great eminence, the strength of the opposition would have obliged him to renounce public teaching, had he not eluded all their efforts by the expedient of adopting the name of another as a sanction to his proceedings. His reputation was now greatly extended; but still he declined private practice, till he should be established in some distinguished public station. In 1776 he was admitted a member of the corporation of surgeons; and so limited were his finances at this time, that he was indulged by that body in paying his fees at his own convenience. He successively filled the honourable stations in the corporation and academy of surgery; and in 1782 he was appointed surgeon-major to the hospital De la Charité.

Desault was now regarded as one of the first surgeons of Paris. He succeeded to the next vacancy at the Hôtel Dieu; and, after the death of Moreau, almost the whole surgical department of that hospital was intrusted to him. Here he instituted a clinical school of surgery on a liberal and extensive plan, which attracted a great concourse of students, not only from every part of France, but also from foreign countries. An audience composed of about 600 students frequently met to hear his instructions; and most of the surgeons of the French army derived their knowledge from his lectures. He introduced many improvements into the practice of surgery, as well as in the construction of various surgical instruments.

In 1791 he published a work entitled Journal de Chirurgie, the object of which was to record the most interesting cases which had occurred in his clinical school, with the remarks which he had made upon them in the course of his lectures. The editing of this work was intrusted to his pupils. But in the midst of his valuable labours he became