An introducer sheath has an inner fluorocarbon liner, a reinforcing member disposed radially outwardly from the liner, and a polymeric intermediate layer positioned longitudinally over the reinforcing member and inner liner. A heat shrink layer formed of a block copolymer having cross-linked and non-cross-linked functional groups comprises an outer layer of the sheath. During formation of the introducer sheath, the intermediate layer is melted and compressed in the heat shrink layer in a manner such that the inner surface of the intermediate layer bonds to the outer surface of the inner liner through spacings of the reinforcing member, and the outer surface of the intermediate layer bonds with non-cross-linkcd active functional groups of the heat shrink layer.