The ultraviolet light radiation stability as manifested, for instance, by the resistance to yellowing is improved for polyphenylene ether resins and blends by including a combination of a benzotriazole-based screening-type UV stabilizer and a hindered dipiperidinyl antioxidant-type UV stabilizer. The combination of the two stabilizers exhibits syneristic behavior in the compositions, conferring better resistance to yellowing than can be predicted and expected from the observed effects of each stabilizer alone. Flame retardant embodiments are illustrated.