Eumenes mediterraneus can reach a length of about 15 millimetres. Body is black with yellow markings. Clypeus is mainly yellow and scutellum has two large spots. Tergite I has a broad apical yellow band. Tergite II has two large yellow bands laterally and a pale and translucent apical lamella. Tergites V and VI have a yellow apical band.
In males antennae are curled at tip. In females the segment between the compound eyes is yellow with black spots in inferior part.