Diaz went to work at age 17 for a printer, and then for a manufacturer of porcelain. In his early twenties he copied paintings in the Louvre, teaching himself technique by mimicking the styles of the likes of Rembrandt van Rijn and Antonio da Correggio. At 31, he debuted at the Salon. Five years later, he settled in the village of Barbizon a little to the southeast of Paris.
Success began to follow Diaz when he settled on painting landscapes. The view of the Fontainebleau forest—one of many he created over the course of his career—that he showed at the Salon of 1844 won a third-class medal; the medals kept coming through the 1840s. Diaz received the Legion of Honor in 1851. After that, his paintings sold so well that he stopped exhibiting at the Salon. By the 1880s, American collectors with names like Morgan, Vanderbilt, Drexel, and Walters owned his work.