40K-40Ar ages on biotite (227±7 m.y.) and hornblende (244±8 m.y.) and a 238U-208Pb age on sphene (230±5 m.y.) were determined for a diorite from the Eisenkappel intrusion from Southern Carinthia in Austria. The intrusion is stratigraphically dated at younger than Lower Carboniferous. The isotopic results suggest the diorite was emplaced between the Upper Permian and the Lower Triassic.