The herbarium of Vincenzo Cesati (1806-1883) is considered the most important historical collection of the Herbarium of the University of Roma “La Sapienza” (RO), where it is kept as a separate collection under the name of Erbario Cesati. The study of this herbarium is particularly complex on account of the abundance of its different collections (more than 350,000 specimens), the variety of their geographical origins, both European and non-European, and the contribution of a great number of correspondents. Furthermore, mention should be made of the many correlated documents, which only partially have been kept with the herbarium. Nevertheless, the Herbarium (RO) has since several years started to study and to inform about the value of this collection. More recently a computerised databank has been created so that it’s now possible to obtain detailed information on parts of the collection