The invention relates to a continuous process for producing chlorine dioxide comprising the steps of continuously: a) feeding to a reactor (1) an acid, hydrogen peroxide and alkali metal chlorate; b) reacting the alkali metal chlorate with the acid and the hydrogen peroxide to form a product stream (2) containing chlorine dioxide, oxygen and alkali metal salt of the acid, c) bringing the product stream from the reactor to an eductor (3) and mixing it with motive water fed to the eductor and thereby forming a diluted product stream; d) removing oxygen from the diluted product stream; e) withdrawing part of the diluted product stream (9), before, during or after the step of removing oxygen; f) adding water (11) to the non-withdrawn part of the diluted product stream to form a recycle stream (12); and, g) bringing the recycle stream (12) to the eductor and feeding it thereto as motive water (4). The invention further relates to a production unit for the production of an aqueous solution comprising chlorine dioxide.