The reaction of 2 equivalents of 1,3-dimesitylimidazolium chloride with Cp3Yb affords the salt [bis(1,3-dimesitylimidazolium)cyclopentadienide] [bis(cyclopentadienyl)dichloroytterbate]; the T-stacked cation is composed of two imidazolium fragments that are C–H⋯C(π) hydrogen bonded to the bridging cyclopentadienide anion.