Materials and Methods: This clinical study was carried at oral and maxillofacial surgery department at Hama University. This study included random sample of 40 cases of impacted lower third molars. The ages of patients were between 18-25 years. The sample was divided into two groups: First group: 20 impacted lower third molars was surgically extracted. Hyaluronic acid 0.2 % was applied in the alveolar cavity with surgical suture. Second group: 20 impacted lower third molars was surgically extracted. Chlorhexidine 0.2% was applied in the alveolar cavity with surgical suture.

Results: There was significant difference between two groups in edema (p<0.05) on the 2^nd and 3^rd days for the first group (Hyaluronic acid 0.2 %) while there was no significant difference between two groups in edema on the 7^th day after surgery. There was significant difference between two groups in pain (p<0.05) on the 1^st and 2^nd days for the first group (Hyaluronic acid 0.2 %), while there was no significant difference between two groups in pain on the 3^rd day after surgery.

Conclusion: The study showed that both of Hyaluronic acid and Chlorhexidine 0.2% have a positive effect on controlling pain and edema after surgical extraction, with preference for Hyaluronic over Chlorhexidine 0.2%.