A process for joining, by spark plasma sintering, at least two refractory ceramic parts, each of the parts having at least one surface to be joined by spark plasma sintering, in which surfaces to be joined are brought into contact without addition of any sort between the surfaces. Then, a joining pressure of 1 to 200 MPa is applied to the ceramic parts. A pulsed electric current having an intensity of 500 A to 8000 A is applied to the ceramic parts so as to raise the temperature of the parts to a joining temperature of at least 1300° C. Then, the electric current is terminated simultaneously with the pressure, and the parts are cooled, and the joined parts are recovered.