Secretos de chirurgia, en especial de la enfermedades de morbo-galico y lamparones, y asimismo la manera como se curan los indos las llgas y heridas, y otras pasiones en las Indias, muy útil y provechoso par España, y otros muchos secretos de chirugia hasta ahora no escritos.

Arias de Benevides travelled to the New World where he observed native remedies and reported them in this book. In the book he also described his performance in Mexico City (1561) of the first neurosurgical intervention on the North American continent, in which he operated on a 13-year-old boy who had sustained head trauma that caused an open depressed cranial facture and exposed the cerebrum.