Abstract: The present invention relates to a method for treating waste comprising at least one organic phase, said method comprising the following consecutive steps: a) preparation of an oil-in-water emulsion with controlled TOD using waste to be treated comprising at least one organic phase, by mixing said waste with an aqueous phase in a mixer, preferably with high shear; b) possible adjustment of the TOD of the emulsion obtained in step a); and c) hydrothermal oxidation, under subcritical or supercritical starting conditions, of the emulsion thus obtained. The present invention also relates to a facility suitable for implementing the method for treating waste comprising at least one organic phase according to the invention.