Abstract: The present invention relates to new benzoyl-phenyl-piperidine derivatives selected from the group consisting of:(i) 2-piperidinobenzophenones of the general formula: ##STR1## in which: R.sub.1, R.sub.2 and R.sub.3, which are identical or different, each represent an atom of hydrogen, a hydroxy group, CF.sub.3, a halogen, a lower alkyl group or a lower alkoxy group;R.sub.4 represents an atom of hydrogen, a halogen, an NO.sub.2 group, an NR'R" group [where R' and R", which are identical or different, represent an atom of hydrogen, a lower alkyl group or a CO.sub.2 R group (where R represents a lower alkyl group or a benzyl group)];R.sub.5 and R.sub.6, which are identical or different, each represent an atom of hydrogen, a C.sub.1 -C.sub.4 -alkyl group, an OH group, a phenyl group or a benzyl group; and(ii) acid addition salts thereof.The invention also relates to the method for preparing these new derivatives and to their use in therapeutics, particularly as immunostimulant and immunoadjuvant agents.