The invention concerns 1,8-dihydroxy-9-anthrones substituted in the 10-position of the formula: ##STR1## in which R.sub.1 represents a group taken from the set constituted by: ##STR2## wherein R.sub.2 represents H, C.sub.1-8 alkyl, C.sub.1-3 mono- or poly-hydroxyalkyl, carbamoyl or phenyl,R.sub.3, R.sub.4, and R.sub.5 represent H, C.sub.1-8 alkyl, C.sub.3-8 mono- or poly-hydroxyalkyl, possibly interrupted by an oxygen, C.sub.3-6 cycloalkyl, or R.sub.3 and R.sub.4 form a divalent group: --(CH.sub.2).sub.(4 or 5) --, --(CH.sub.2).sub.2 --O--(CH.sub.2).sub.2 --, or --(CH.sub.2).sub.2 --N(R.sub.8)--(CH.sub.2).sub.2 --, R.sub.8 being H, --CH.sub.3, or --CH.sub.2 CH.sub.2 OH,R.sub.6 represents --CO.sub.2 R.sub.5, --CN, CHO, --CONH.sub.2, or --CONH--CH.sub.2 OH,and R.sub.7 and R'.sub.7 are H or --CH.sub.3, and their optical isomers.Utilization of the compounds (I) in human or veterinary medicine, in particular in the treatment of psoriasis and of warts, in cosmetics.