A process for the preparation and purification of the sodium salt of hyaluronic acid from the fermentation broth of Streptococcus or Bacillus or from rooster combs comprising the following steps: B. extraction, comprising the following steps: B1. addition of Celite to a medium containing non-purified HA and complexing of HA with Cetyl Pyridinium Chloride, under stirring for at least 30 minutes and following sedimentation for at least further 30 minutes; B2. elimination of the liquid phase formed in step B1; B3. solubilization of the HA present in the solid phase in an aqueous solution of NaCl and collection of a first extract as sodium salt of HA; this procedure B3 being effected from 1 to 4 times; B4. joining the extracts coming from step/s B3; B5. addition of an aromatic resin having a pore radius ranging from 200 to 300 Angstrom to the joined extracts of B4, the resin composed of crosslinked polystyrene matrixes being preferred, leaving under stirring for at least 8 hours; B6. filtration of the mixture coming from step B5; C. purification, comprising the following steps C1. addition of an aqueous solution of NaOH to the filtrate obtained from step B6; C2. neutralization to a pH ranging from 8 to 9, preferably with HCl; C3. at least one filtration; C4. precipitation and at least one washing of the sodium salt of HA obtained in step C3 with ethanol, final washing in an organic solvent, preferably acetone; C5. drying of the sodium salt of HA, preferably between 25 and 40°C for not less than 15 h, under vacuum. B. extraction, comprising the following steps: B1. addition of Celite to a medium containing non-purified HA and complexing of HA with Cetyl Pyridinium Chloride, under stirring for at least 30 minutes and following sedimentation for at least further 30 minutes; B2. elimination of the liquid phase formed in step B1; B3. solubilization of the HA present in the solid phase in an aqueous solution of NaCl and collection of a first extract as sodium salt of HA; this procedure B3 being effected from 1 to 4 times; B4. joining the extracts coming from step/s B3; B5. addition of an aromatic resin having a pore radius ranging from 200 to 300 Angstrom to the joined extracts of B4, the resin composed of crosslinked polystyrene matrixes being preferred, leaving under stirring for at least 8 hours; B6. filtration of the mixture coming from step B5; B1. addition of Celite to a medium containing non-purified HA and complexing of HA with Cetyl Pyridinium Chloride, under stirring for at least 30 minutes and following sedimentation for at least further 30 minutes; B2. elimination of the liquid phase formed in step B1; B3. solubilization of the HA present in the solid phase in an aqueous solution of NaCl and collection of a first extract as sodium salt of HA; this procedure B3 being effected from 1 to 4 times; B4. joining the extracts coming from step/s B3; B5. addition of an aromatic resin having a pore radius ranging from 200 to 300 Angstrom to the joined extracts of B4, the resin composed of crosslinked polystyrene matrixes being preferred, leaving under stirring for at least 8 hours; B6. filtration of the mixture coming from step B5; C. purification, comprising the following steps C1. addition of an aqueous solution of NaOH to the filtrate obtained from step B6; C2. neutralization to a pH ranging from 8 to 9, preferably with HCl; C3. at least one filtration; C4. precipitation and at least one washing of the sodium salt of HA obtained in step C3 with ethanol, final washing in an organic solvent, preferably acetone; C5. drying of the sodium salt of HA, preferably between 25 and 40°C for not less than 15 h, under vacuum. C1. addition of an aqueous solution of NaOH to the filtrate obtained from step B6; C2. neutralization to a pH ranging from 8 to 9, preferably with HCl; C3. at least one filtration; C4. precipitation and at least one washing of the sodium salt of HA obtained in step C3 with ethanol, final washing in an organic solvent, preferably acetone; C5. drying of the sodium salt of HA, preferably between 25 and 40°C for not less than 15 h, under vacuum.