Abstract: A honeycomb sandwich cast for supporting human or animal body portions. The cast has inner and outer cast layers which, in the finished cast, are rigid, and a central honeycomb core having honeycomb cells which are perpendicular to the skin of the underlying body portion. The honeycomb is securely attached, e.g., mechanically locked or bonded to the cast layers to form an integral, high strength, low weight honeycomb structure. An indentable, resiliently compressible fabric such as reticulated plastic foam may optionally be positioned between the faces of the honeycomb core and the cast layers. With use of such a foam, when the outer layer is applied normally by wrapping a bandage-like fabric about the body portion and the surrounding honeycomb core, a compressive force is generated which presses portions of the foam structure into the honeycomb cell openings to form a more secure interlock and prevent relative movement between the components of the cast.