An unusual triply-bridging cyclopentadienyl (C₅H₅ = Cp) ligand has been characterised in the tetranuclear palladium cluster [Pd₃^II(μ-OAc)₄(μ₃-Cp)Pd⁰(η⁵-Cp)] (1). It is coordinated in the μ₃-η¹:η²:η² mode to a [Pd₃]⁴⁺ triangular subunit of the mixed-valence cluster 1.