The present invention relates to a method for preparing an aqueous gel based on metronidazole, comprising the successive steps consisting in: (A) forming a solvent medium M comprising water and propylene glycol； (B) dissolving the metronidazole in this solvent medium M, and optionally diluting the medium obtained by addition of water, whereby a solution S of metronidazole is obtained； and then (C) mixing the solution S obtained with a gelling polymer, in a sufficient quantity to ensure gelling of the composition. The invention also relates to the aqueous gels of high stability which may be obtained according to this method, and the use of these gels as dermatological compositions .
