Riolan, the son of Jean Riolan, senior (1539-1606), a leading member of the Medical Faculty of Paris, received his medical degree in 1604. He was appointed to the new chair of Anatomy and Botany at the University of Paris, and to the chair of Medicine at the Collége royale. In 1633 he became the principle surgeon to the Queen Mother, Marie de' Medici. A conservative in medical matters, defending Galenic orthodoxy, Riolan opposed Harvey's theory of the circulation of the blood, positing his own theory to which Harvey responded in print.