Two Middle Miocene forms of Plesiodimylus are described from the Devinska Nova Ves-Fissures site (the Middle Badenian, MN 6). Whereas the smaller form represents the typical individuals of P. chantrei, the larger one represents a different new species (P. similis sp. nov.) with an affinity to P. crassidens from the Anatolian Middle Miocene (MN 7/8).