Abstract: A use for synergistic additives for polyamides is disclosed by forming a uniform and intimate mixture with polyamide with a component system selected from (I) (II) or (III) (on a weight basis) where(I) is from 0.01% to 1% of a sterically hindered phenyl phosphonite (Ia) with from 0.05% to 5% of a non-hydroxyl substituted oxanilide(Ib) (together 1a+1b), or Ia together with an aromatic di-carbonyl compound containing two hindered amine moieties (together Ia+c). Preferably the weight ratio of Ia to Ib and Ia to Ic is from 1:3 to 1:10, more preferably 1:4, 1:5 or 1:6 and most preferably 1:5; and(II) is from 0.05 to 5% of a non-hydroxyl substituted oxanilide containing at least two hindered amine groups (a) together with from 0.05 to 5% of the aromatic di-carbonyl compound (b), (II a+b),or (III) from 0.01% to 1% of a sterically hindered phenyl phosphonite, from 0.05 to 5% of a non-hydroxyl substituted oxanilide, and from 0.05 to 5% of an aromatic di-carbonyl compound.