The present invention relates to a process for preparing 2,2'-bis(diphenylphosphinylmethyl)-1,1'-binaphthyls by reacting a reaction mixture prepared in a solvent by reaction of 2,2'-dimethyl-1,1'-binaphthyl with a brominating agent to produce a mixture comprising 2,2'-bis(bromomethyl)-1,1'-binaphthyl and further brominated binaphthyls and optionally further comprising unreacted brominating agent, reacted brominating agent and solvent, with an alkyl diphenylphosphinite of the formula RO--P(Ph--(R').sub.n).sub.2, where R is an alkyl radical having from 1 to 5 carbon atoms, Ph is phenyl, R' is an alkyl radical having from 1 to 4 carbon atoms, CF.sub.3, fluorine, chlorine or bromine and n is 0, 1 or 2, at from 70.degree. to 180.degree. C. optionally in the presence of a further solvent.