Abstract: A mould for producing profiled elements of plastics material, notably in building joinery frames, comprises upper and lower half-moulds which are separated by a joint plane and respectively associated with tightening means, namely the plates of a press and define together the impression of a profiled element to be moulded from said plastics material. Each of said half-moulds has lateral faces parallel to said profiled element and transverse ends and comprises a shoe having an outer surface including removable fastening means cooperating with said tightening means and an inner surface parallel to said joint plane and forming the bottom of said impression. Interchangeable profile-defining members are respectively fixed to said inner surface and form the sides of said impression, thus permitting the production of a large variety of profiled elements for a very low cost price whilst being easy to produce.