A practical and additive-free method for the prenylation of chalcones using prenylzinc is reported. The protocol described is attractive because it provides access to a new class of prenylated chalcone derivatives derived from two classes of natural products in a simple, high-yielding and regioselective synthetic step. Furthermore, the application of other allylic reagents in our new protocol is demonstrated. A plausible mechanism that invokes steric factors to account for the α-regioselective outcome is proposed.