Abstract. The treatment of methylchlorodisilanes with ethynyldigrignard (BrMgCECMgBr) resulted in oligomeric as well as polymeric ethynyldisilanes. The kind of this products is related to the chloro functionality of the starting disilane. The reaction of SiC1Me (SiC12Me) 2 as well as SiMe (SiCl2Meh yielded polymers beside small amounts of the monomeric products (HC= C) MeSi [SiMe (C= CH) 2] 2 and MeSi [SiMe