To provide a new method for producing para-dichlorobenzene, which satisfies both high selectivity of para-dichlorobenzene and high chlorine conversion rate.

The method for producing para-dichlorobenzene comprises nuclear chlorination reaction of benzene and/or chlorobenzene by chlorine molecules in the presence of a Lewis acid catalyst and a co-catalyst. The method comprises steps of: previously continuously feeding a mixed solution of benzene and/or chlorobenzene, the Lewis acid catalyst and the co-catalyst to a reactor; continuously feeding chlorine gas to the reactor through a separate line; stirring and reacting the same; and continuously taking out a reaction liquid containing the resulting para-dichlorobenzene.