A shaped insulation insert, an insulated concrete wall structure, and a method of producing same is disclosed. The insert is to be embedded in a concrete wall and comprises an elongate, rigid foam insert including an integrally formed base section and cap section symmetrically disposed on the base section. The elongate insert has a length sufficient to form a vertical interior surface expanse of the concrete wall, and flat side surfaces that are sufficient to enable a plurality of inserts to be placed horizontally side-by-side to form a horizontal interior surface expanse of the concrete wall. The insert includes opposed end sections extending from outer ends of the intersection of the cap and base sections to an outer edge portion for disposing adjacent inserts in the concrete wall. The insulated concrete wall structure comprises an interior section including an inner insulation portion effective to produce a saving of concrete. The insulation portion includes a plurality of shaped elongate insulation inserts embedded in an outer concrete portion.