Aromatic poly(ether-amide)s (PEAs) based on -(R-1,R-2)diphenylsilane- and oxyether units were synthesized by direct polycondensation of a diamine and two dicarboxylic acids. For this, the diamine bis(4-(4-aminophenoxy)phenyl)ethylmethylsilane was obtained by reduction of the respective dinitro compound, which was synthesized by nucleophilic aromatic halogen displacement from 1-fluoro-4-nitrobenzene with bis(4-hydroxyphenyl)ethylmethylsilane in basic medium. New silicon-containing aromatic diamine and the PEAs were characterized by elemental analysis, FT-IR, H-1, C-13 and Si-29 NMR spectroscopy and the results were in agreement with the proposed structures. The incorporation of aliphatic units such as methyl and/or ethyl groups on the silicon atoms affected positively the solubility of the PEAs in organic polar solvents. When their thermal and optical properties were compared with two PEAs of similar structure, containing phenyl groups bonded to the silicon atoms, it was observed a decrease of the glass transition temperature and transmittance values, maintaining a high thermal resistance.