Abstract. The boundary between the Pannonian and Pontian (late Miocene) of the Pannonian area is recognised on the basis of ostracod faunas. A comparison is made between the faunas of the Pannonian Basin and the Dacic-Euxine Basin. A transitional fauna with Pannonian elements, but a stronger Pontian component, is described from Cimpia (Romania). This indicates a more gradual transition between the two stages in the Pannonian Basin than in the Dacic-Euxine Basin, where there is a sharp faunal break indicating a period of non-deposition or erosion.