The invention relates to a process for continuously preparing polyamide oligomers. This comprises continuous conveying of an aqueous solution of polyamide-forming monomers from a reservoir vessel into an oligomerization reactor, heating of the aqueous solution beyond a dissolution or storage temperature, the residence time of the monomer solution in the oligomerization reactor being limited and the pressure or the partial vapor pressure of the water being adjusted such that a conversion of monomers to polyamide oligomers does not exceed a maximum value and/or the polyamide oligomers formed do not phase-separate or spontaneously crystallize in solid form, and continuous discharge of the polyamide oligomers from the oligomerization reactor. A polyamide oligomer preparable by this process can be provided continuously in a mixture with water in a process for preparing a semicrystalline or amorphous, thermoplastically processible polyamide and then postcondensed to give a polyamide. This polyamide can be used for production of moldings by means of injection molding, multicomponent injection molding, injection molding/welding, extrusion, coextrusion, blow molding or thermoforming.