Abstract: New tert-butyl derivatives of benzylidenecamphor, process for preparing them, their use as antioxidant agents and cosmetic and pharmaceutical compositions containing them.The invention relates to benzylidenecamphor derivatives of formula: ##STR1## where R is hydrogen or a tert-butyl residue, R.sub.1 is a C.sub.1 -C.sub.8 alkyl or alkoxy residue, and R.sub.2 and R.sub.3 denote hydrogen or hydroxyl, at least one of the two being hydroxyl, to a process for preparing them and to their uses as antioxidants, broad-band sunscreens and medicinal products for the preventive treatment of skin allergies and inflammations as well as for the prevention of certain cancers.