The present invention relates to a homogeneous aqueous solution of injectable chitosan containing, in a physiologically acceptable medium, between 0.1 and 4.5% by weight of a chitosan having a degree of acetylation less than 20% and a weight average molecular mass of between 100,000 and 1,500,000 g/mol, said solution having a pH greater than or equal to 6.2, and advantageously between 6.2 and 7.2, said solution not containing chitosan having a degree of acetylation greater than 20%, said solution being liquid and homogeneous at ambient temperature. The invention also relates to an aqueous solution as previously described, characterised in that it is preparable by a method comprising at least the following steps: - dissolving the chitosan in water by adding acid such as a weak acid, said weak acid being advantageously chosen from the group consisting of acetic acid, glycolic acid, lactic acid, glutamic acid, and the mixtures of same, and - readjusting the pH by dialysis, preferably at ambient temperature, in order to obtain an aqueous solution having a pH greater than or equal to 6.2, advantageously between 6.2 and 7.2, and preferably between 6.25 and 7.1.
