A series of novel polyisocyanide-graft-polystyrenes and polyisocyanide-graft- [polystyrene-block-poly(butylacrylate)]s were synthesized through the grafting-through and grafting-from routes with two types of living polymerization techniques: polymerization with the Pd-Pt mu-ethynediyl dinuclear complex as the initiator and catalyst for the polyisocyanide backbone and atom transfer radical polymerisation for the grafted side chain. Through the introduction of a chiral center at the side chain of the polyisocyanide backbone, helical grafted and graft block polyisocyanides were prepared through the grafting-from method. All of the obtained polymers exhibited polydispersities in the range of 1.07-1.41. This might have been the first time grafted polyisocyanides were prepared, especially helical grafted polyisocyanides, through the operation of two living polymerization techniques. (C) 2003 Wiley Periodicals, Inc.