Phaedrus may be defined, in a certain sense, as one of the greatest glories of Latin literature, because he is the first known author in Greek and Roman culture who presents us with a collection of fables conceived as an autonomous work of poetry, destined to be read. Furthermore, Phaedrus inspired directly or indirectly an enormous part of European fables. Despite the importance of Phaedrus in the history of European culture, the critical editions of this poet in use today are philologically unsatisfactory: as a matter of fact, some of them are excessively conservative, others are marred by unnecessary textual conjectures. This new edition, which offers an extensive apparatus of fontes and testimonia, solves a number of philological problems and presents a sounder text than the ones established by previous editors; the critical apparatus is based on a fresh examination of the extant manuscripts and the indirect transmission, and on a careful evaluation of the philological studies which have appeared since Pithou's editio princeps (1596).