The synthesis of poly(alkynylstannanes) was achieved by the step-growth polymerization of bisaminostannanes and α,ω-diynes. This is a new class of organotin polymers containing tin-alkyne linkages in the polymer backbone. The polymers were obtained in good yield, albeit with relatively low molecular weight. The polymers underwent crosslinking on standing to give insoluble material and required stabilization with radical inhibitors. The thermal properties of these materials, and the influence of the group pendent to tin are discussed. © 1986 Springer-Verlag.