The π-coordinated interaction of a palladium atom with acetylene and ethylene is investigated through theoretical calculations, including electron correlation effects. The interaction is analysed as a van der Waals one and it is concluded that the ground state of PdC2H2and PdC2H4molecules are bound by 48·93 kJ mol-1and 85·85 kJ mol-1relative to the ground state of the Pd (1S) atom, C2H2(1Σg) and C2H4(1Ag) molecules. A comparison with experimental results for this system is presented.