The Gelasian site of Coste San Giacomo (CSG) (central Italy) provides a unique opportunity to investigate the faunal and environmental changes occurred in Mediterranean Europe during the Early Pleistocene. The finding of both large and small mammal fauna has a great biochronological and palaeoenvironmental value.

In this work the description of the small mammal assemblage is presented and discussed in detail for the first time. Twelve taxa, belonging to three orders, have been in fact identified and described (six Rodentia, one Lagomorpha and five Eulipotyphla). In particular, the CSG small mammal assemblage has provided the largest collection in Europe of \emph{Mimomys pliocaenicus} and, for this reason, it can be considered as a reference. Finally, the occurrence of the Desmaninae subfamily is reported for the first time in Italy.