The stability of the high oxidation states +3 and +5 in Group 11 fluorides is studied by relativistic Moller-Plesset (MP) and coupled cluster methods. Higher metal oxidation states are stabilized by relativistic effects. As a result, the hexafluoro complex of the Group 11 element with nuclear charge 111 and oxidation state +5 is the most stable compared to the other congeners. The results also suggest that AgF6- is thermodynamically stable and, therefore, it might be feasable to synthesize this compound. For the copper fluorides we observe very large oscillations in the Moller-Plesset series up to the fourth order. Nonrelativistic calculations lead to the expected trend in the metal-fluorine bond distances for the MF2- compounds, CuF2- < AgF2- < AuF2- < (111)F-2(-). However, relativistic effects change this trend to CuF2- < AuF2- < (111)F-2(-) < AgF2-. Vibrational frequencies are predicted for all compounds. Where experimental data are available, they generally agree very well with our calculated results.