This work describes the synthesis, characterization and thermal studies of poly(esters) (PEs) containing two Si atoms in the main chain, derived from aromatic diacids and aliphatic dialcohols in which the Si atom is bonded to methyl and/or ethyl groups. PEs were characterized by FT-IR and H-1, C-13 and Si-29 spectroscopy and the results were in agreement with the proposed structures. Poly(esters) were soluble in polar aprotic solvents, such as DMSO and DMF, and acetone, and partially soluble in ethanol. The inherent viscosity and glass transition and thermal decomposition temperatures, h(inh), Tg and TDT respectively, were determined. These results showed that PE-2 and PE-4, derived from the dialcohol with the Si(CH3)(CH2CH3)-moiety as central element, had the larger values of h(inh), Tg, TDT and the residual weight alter heating at 900 degrees C, indicating that the specific structure of aliphatic dialcohols control the reaction.