PuCoGa 5 with 18.5K has an extremely high T c for superconductivity compared with other actinide materials having T c s around 2–3K. It appears to be a “high T c superconductor” in the field of actinides. After nearly 20 years of research in high T c superconductors only Cu containing materials have T c s above about 30K (exception MgB 2 ). BCS theory cannot explain such high transition temperatures, thus other or additional coupling mechanisms, like magnetic exchange are necessary. Mixed valence, spin holes in an antiferromagnetic lattice, small energy difference between the various valences and two-dimensionality are common features of Cu and Pu containing superconductors. It can be shown in this paper that the mechanism for superconductivity is the same for Cu and Pu containing materials.