Purpose: To evaluate the efficacy of hyaluronic acid to improve the healing of surgical incisions in the oral cavity. Materials and methods: Six Italian private practices participated in this trial, each centre provided 12 patients. After suturing, patients were randomised to receive either a single application of 0.8% hyaluronic acid or a placebo (the carrier). Outcome measures were: assessment of wound healing 10 days post-operatively on a Likert scale by the blind operators and by an independent and blinded outcome assessor on the photographs, adverse events and post-operative complications. Reproducibility was assessed by evaluating agreement between operators and the independent outcome assessor using the weighted Kappa statistic. Results: Thirty-six patients were evaluated in each group, at ten days none had dropped-out. No post-operative complications or adverse events occurred. There were no statistically significant differences for wound healing, assessed clinically by the blinded operators or on photographs evaluated by a blinded and independent outcomes assessor. There was a substantial agreement between operators and the independent outcome assessor in the wound scoring. Conclusions: Hyaluronic acid placed over surgical incisions in the oral cavity does not appear to improve wound healing. Further trials are needed to better understand the potential role of hyalulonic acid in dental applications. Parole chiave: hyaluronic acid, multicentre randomised placebo-controlled clinical trial, oral cavity, wound healing