X-ray photoelectron spectroscopy was used to study the formation of the interface between vapour-deposited Al and the organometallic polymer [-Pd(PBu3)(2)-C=-C-C6H4-C6H4-C=C-](n) (Pd-DEBP), for Al coverage up to 50 Angstrom. Core level analysis reveals that aluminium reacts primarily with the palladium atoms in the polymer chain by charge transfer from Al towards Pd. Al reacts and tends to diffuse some distance into the polymer film before agglomerating into metallic islands, There is no apparent interaction between Al and the organic moiety of the polymer. The C 1s shake-up structure remains unmodified over the whole range of Al coverage, and no appearance of carbide-like C Is signal has been detected. Subsequently to the Al-Pd interaction, aluminium seems to interact with an oxygenated species in different sites where phosphorus is present.