A stabilized thermoplastic resin composition is provided which comprises the following components (i), (ii) and (iii):(i) 100 parts by weight, based on the total amount of the following (A), (B) and (C), of a mixture comprising (A) about 10-100% by weight of a polyphenylene ether, (B) 0-about 90% by weight of an alkenyl aromatic resin, and (C) 0-about 90% by weight of a crystalline thermoplastic resin, total amount of (A) and (B) being at least about 15% by weight of the total amount of (A), (B) and (C),(ii) 1-50 parts by weight of an alkenyl aromatic elastomer (non-hydrogenated), and(iii) a stabilizer comprising (D) 0.01-5 parts by weight of a sulfur compound and (E) 0.01-5 parts by weight of at least one phenol compound.