He studied medicine in Paris, and in 1850 became a surgeon of Parisian hospitals.
During his career, he practiced surgery at the Lourcine, Cochin, Hôpital Saint-Louis and Hôtel-Dieu.
In 1868 he became a member of the French Académie Nationale de Médecine.
In 1870, Guérin introduced the practice of using cotton-wool bandages for prevention of wound infections.
He was a specialist in urologic surgery, and has a handful of genitourinary terms that contain his name: