Abstract: Sterically hindered piperidines having at least 5 alkyl groups in ring positions 2,3,5 and 6 are usable as light-stabilizers for organic polymers. The nitrogen may be unsubstituted or may bear a mono- to tetravalent substituent. The compounds can be synthesized by a Wolf-Kishner reduction of polyalkyl 4-oxopiperidines optionally followed by a N-substitution reaction in a second step.The stabilizers are added to the polymers in an amount of from 0.01 to 5% by weight. Preferred is the stabilization of polyolefins, styrene polymers, polyamides and polyurethanes.