Background: The purpose of this review is to systematically evaluate the effects of an essential-oil mouthwash compared to a chlorhexidine mouthwash with respect to plaque and parameters of gingival inflammation.Methods: PubMed databases were searched for studies up to and including may 2015. A comprehensive search was designed and the articles were independently screened. Articles that evaluated the effects of the essential oil mouthwash compared to chlorhexidine mouthwash were included. A meta-analysis was performed, and weighted mean differences were calculated.Results: A total of 17 unique articles were found, of which 11 articles met the eligibility criteria. A meta-analysis of long-term studies (duration > 3 months) showed that the essential oil mouthwash provided significantly better effects regarding prophylactic plaque control than chlorhexidineConclusion: In long-term use, the standardized formulation of essential oil mouthwash is more reliable than chlorhexidine mouthwash.