Objective: The efficacy of a topical application of hyaluronic acid (HA) was tested for treating gingivitis. Method and materials: Sixty nonsmoking outpatients in good general condition, with clinical signs of gingivitis, were included in the study. Forty patients (HA group, 20 men, 20 women; age: 32.8 ± 11.3 years) used a spray containing HA 5 times daily over a period of 1 week. The control group consisted of 20 patients (10 men, 10 women; age: 31.3 ± 9.3 years). The clinical parameters DMF-T (decayed, missed, filled teeth) index, approximal plaque index, sulcus bleeding index, papilla bleeding index, and gingival crevicular fluid were measured at baseline (T1), after 3 days (T2), and after 7 days (T3). Results: A reduction in the sulcus bleeding index of the HA group (T1: 72.9 ± 19.5%) to 50.3 ± 21.1% was noted at T2, and at T3 the sulcus bleeding index was 40.7 ± 23.0%. The papilla bleeding index values of the HA group were 1.6 at T1, 1.0 at T2, and 0.7 at T3. The gingival crevicular fluid showed significant reductions in the HA group. At T1 the recorded mean value was 16.3, at T2 it was 11.8, and at T3 it was 7.9. Only insignificant changes were observed in the respective indices of the control group. There were no significant alterations in the plaque values of either group throughout the study period. Conclusion: The results obtained by this study demonstrate that the topical application of an HA-containing preparation represents a potentially useful adjunct in the therapy of gingivitis, although its use does not diminish the need for plaque reduction as a primary therapeutic measure. Keywords: gingivitis, gingivitis therapy, hyaluronic acid