OBJECTIVE To evaluate the efficacy of chlorhexidine-thymol varnish (Cervitec Plus(®)) as an adjunct to scaling and root planing in the improvement of periodontal parameters. METHODS A split mouth randomized clinical trial was conducted in 25 subjects with chronic periodontitis receiving scaling and root planing alone and as an adjunct to chlorhexidine-thymol varnish (Cervitec Plus(®)) and chlorhexidine-thymol varnish (Cervitec Plus(®)) alone. Clinical examinations were performed at baseline, 1 month and 3 months. RESULTS Short term advantages were observed in the clinical parameters in subjects receiving scaling and root planing and an adjunct, chlorhexidine-thymol varnish (Cervitec Plus(®)) who showed the greatest improvement in the periodontal parameters at 3 months. CONCLUSIONS Subjects with chronic periodontitis significantly benefit from scaling and root planing when used with an adjunct, chlorhexidine-thymol varnish (Cervitec Plus(®)).