The hydrothermal reaction of (C2H10N2)Ce2F10 with Ni(II) derived from impregnated PTFE autoclave liners results in the formation of [Ni(H2O)6][Ce2F10]·2H2O in the form of aqua-colored single crystals. In this ion-exchange reaction, the [Ce2F10]2- layers remain structurally intact when the ethylenediammonium dications are replaced by [Ni(H2O)6]2+. This methodology appears to be a general one for obtaining single crystals of ion-exchange products of layered Ce(IV) fluorides.