An unusual triply-bridging cyclopentadienyl (C(5)H(5) = Cp) ligand has been characterised in the tetranuclear palladium cluster [Pd(3)(II)(μ-OAc)(4)(μ(3)-Cp)Pd(0)(η(5)-Cp)] (1). It is coordinated in the μ(3)-η(1):η(2):η(2) mode to a [Pd(3)](4+) triangular subunit of the mixed-valence cluster 1.