The present invention provides a process for preparing dinitrotoluene, comprising the steps of a) reacting toluene with nitric acid in the presence of sulphuric acid to give mononitrotoluene, b) separating the reaction product from step a) into an organic phase comprising mononitrotoluene and an aqueous phase comprising sulfuric acid, c) reacting the organic phase comprising mononitrotoluene with nitric acid in the presence of sulphuric acid to give dinitrotoluene, d) separating the reaction product from step c) into an organic phase comprising dinitrotoluene and an aqueous phase comprising sulfuric acid, wherein the reaction product from step a) has a content of toluene of from 3.0 to 8% by weight, based on the organic phase, and a content of nitric acid of from 0.1 to 1.2% by weight, based on the aqueous phase, and the phase separation in step b) is effected in such a way that further reaction of the toluene with the nitric acid is prevented.