The P-H...P interactions were investigated using a model complex phophine dimmer with its three minimum energy conformers on the counterpoise corrected potential energy surface. At the MP2(full)/6-311++G(3df,3pd) level, the basis set superposion error corrected interaction energy of the three minimum energy conformers is-1.26, -0.85 and -0.85kcal/mol, respectively, similar to the MP2 values previously found for the C-H...S, S-H...C, C-H...O and O-H...C interactions. The Natural Bond Orbital analysis confirms that they are not of weak hydrogen bonding and bound only by van der Waals forces.