This invention relates to radiopaque polyurethane compositions that are reaction products of(a) cycloaliphatic diisocyanates;(b) at least one polyester, polycarbonate, and/or polyester carbonate diol having a molecular weight of from about 1000 to about 6000;(c) an isocyanate-reactive bromine-containing aromatic chain extender; and(d) optionally, a catalyst;wherein the quantity of component (c) is such that the amount of bromine in the polyurethane composition is from 10 to 35% by weight, and wherein the components are reacted at an isocyanate index of from 0.95 to 1.2.