The oxidative addition of pure (R(P))-menthyl phenylphosphinate 1 to a platinum (0) complex proceeds readily with retention of configuration at the chiral phosphorus center which was unambiguously confirmed by an X-ray analysis. In the presence of a catalytic amount of palladium, the hydrophosphinylation of a variety of alkynes with 1 also takes place stereospecifically, with retention of configuration, affording high yields of the corresponding vinylphosphinates bearing a single chirality at phosphorus.