The reaction between trans-[AuF2(pyridine)(2)](+) and [PhI(pyridine)(2)](2+) results in the formation of PhIF2 and [Au(pyridine)(4)](3+). Investigation of the reaction pathway using model Pd and Pt analogues of the gold complex indicate that the most likely mechanism is attack by the Au-F onto the I(III), rather than a redox process. This demonstrates that the Au(III)-F fragment can behave in a nucleophilic manner even in a relatively electron-poor cationic complex.