Giorgio Valla owned a Greek manuscript of Dioscorides’ De Materia Medica, a reference work in the field of pharmacology for simple medicines. Today kept at the Biblioteca Estense Universitaria in Modena with the shelf mark α.P.5.17, it is partly autograph and bears a subscription dated 1487. Representative of the earliest studies on the Greek text of Discorides’ in Humanist Italy, this manuscript is of particular interest in many respects, not least because of the conditions under which it was produced and the achievements it led to. This article will therefore consider both the production and usage contexts of the manuscript, which place Giorgio Valla at the centre of a network of humanists interested in compiling and interpreting Dioscorides’ text (Ermolao Barbaro, Angelo Poliziano, Nicolò Leoniceno and Alessandro Bondino), as well as the concrete evidence of how Valla could read and use the treatise.