The catalytic acetoxylation of dialkyl allyl phosphonates with the Pd(OAc)2/benzoquinone/MnO2/HOAc system leads, regioselectively, to dialkyl 3- acetoxy 1-alkenyl phosphonates. On the basis of the regio- and stereoselectivity of the reaction, a mechanism is proposed which involves a (π-allyl) palladium complex as intermediate.