A stabilizer composition comprising (A) a compound of the formula (I) wherein R is (CH.sub.2--CH.sub.2--O--).sub.n, --R.sub.2; --CH.sub.2--CH(OH)--CH.sub.2--O--R.sub.2; or --CH(R.sub.3)--CO--O--R.sub.4; n is 0 or 1; R.sub.2 is C.sub.1-C.sub.13alkyl or C2C.sub.20alkenyl or C.sub.6-C.sub.12aryl or CO--C.sub.1-C.sub.18alkyl; R.sub.3 is H or C.sub.1-C.sub.8 alkyl; R.sub.4 is C.sub.1-C.sub.12alkyl or C.sub.2-C.sub.12alkenyl or C.sub.5C.sub.6cycloalkyl; and (B) one or more compounds selected from benzotriazoles of the formula (IIa), 2-hydroxybenzophenones of the formula (IIb), oxalanilides of the formula (IIc), 2-hydroxyphenyltriazines of formula (IId), cinnamates of formula (IIe), and benzoates of formula (IIf) as defined in claim 1, is especially effective towards stabilizing organic materials against degradation induced by light, heat or oxidation.