45 subjects participated in a double-blind cross-over mouthwash study where a new tablet-form combination of chlorhexidine, fluoride and xylitol (XYLIHEX) was studied together with solutions of chlorhexidine (CHX) and sodium fluoride (NaF). The preparation XYLIHEX was developed as a dental chemotherapeutic that could easily be added to the soldiers' kit to be used under circumstances where practising normal oral hygiene habits is restricted. For comparative purposes, XYLIHEX was prediluted in this study to make a solution. Before starting, professional prophylaxis was given to the subjects to bring their gingivitis index scores as close to 0 as possible. The subjects refrained from mechanical tooth cleaning for three 7-day test periods. Plaque wet weight and periodontal index scores were recorded before and after the test periods. The results showed that the preparations XYLIHEX and CHX did not statistically differ from each other in reducing plaque wet weight values and the recorded periodontal index scores. Both these preparations were statistically highly significantly more effective antiplaque agents than NaF, as expected.