Process for producing venlafaxine and/or physiologically acceptable addition salts thereof, consisting in reacting a compound having the general formula (II) wherein R is a C1-C10 alkyl group, aryl group, aralkyl group or cycloalkyl group having from 3 to 6 carbon atoms, with an organomagnesian compound having the general formula (III) wherein X is a halogen atom and, if desired, a salt of venlafaxine can be obtained by reaction with a physiologically acceptable acid.