A cosmetic or dermatological composition with a depigmenting action comprises derivatives of 2,5-dihydroxyphenylcarboxylic acids, their homologs, and their salts, with the derivatives having the following structural formula: ##STR1## wherein: R.sub.1 represents OR.sub.5, OH, or ##STR2## R.sub.5 is a linear or branched C.sub.1 -C.sub.20 alkyl radical, a linear or branched C.sub.2 -C.sub.20 alkenyl radical, or a C.sub.1 -C.sub.20 alkyl radical substituted by one or more hydroxy or alkoxy groups;r' and r", identical or different, represent a hydrogen atom, a C.sub.1 -C.sub.20 alkyl radical, a C.sub.2 -C.sub.6 hydroxyalkyl radical, or a C.sub.3 -C.sub.6 polyhydroxyalkyl, or r' and r" taken together, with the nitrogen atom, form a heterocycle;the number of carbon atoms in the --(CH.sub.2).sub.n --COR.sub.1 chain is less than or equal to 21;R.sub.2 and R.sub.3, identical or different, represent a hydrogen atom, a linear or branched C.sub.1 -C.sub.4 alkyl radical, or a C.sub.1 -C.sub.4 alkoxy; R.sub.4 represents a hydrogen atom or a linear or branched C.sub.1 -C.sub.4 alkyl radical; andn is an integer from 0 to 20, provided that, when R.sub.2 and R.sub.3 represent a hydrogen atom, n is greater than or equal to 2.