New polyesters containing both silane and "cardo" groups were synthesized by solution polycondensation involving the reaction of bis(4-chlorocarbonylphenyl)dimethylsilane with cardo bisphenols, namely, phenolphthalein, phenolphthalimidine, and phenolphthalein anilide. Copolyesters were obtained by using different proportions of phenolphthalein and phenolphthalein anilide. Polyesters had inherent viscosities in the range 0.22-0.70 dL/g and were readily soluble in chlorinated hydrocarbons and polar aprotic solvents. Polyesters showed glass transition temperatures in the range 168-255 degrees C as measured by DSC and thermogravimetric analysis indicated no weight loss below 416 degrees C in a nitrogen atmosphere.