This parallel controlled clinical trial evaluated the effect of a gel containing Lippia sidoides essential oil on plaque and gingivitis control.Thirty patients (n=30) were randomly selected and allocated into three groups: Lippia sidoides (LS, n=10), chlorhexidine (CLX, n=10) or placebo (control, n=10). Plaque and bleeding index were recorded at baseline and after three months. All volunteers were instructed to brush with the gel three times a day throughout the experiment period.There was a significant reduction on plaque and gingivitis in the test groups (P.05).A gel preparation containing 10% Lippia sidoides essential oil was an efficient herbal antiplaque and antigingivitis agent.