The present study was conducted to assess the efficacy of a new mouthrinse formulation in reducing oral malodour compared to that of commercially available products containing chlorhexidine (CHX) and a negative control. 174 healthy volunteers, each with an organoleptic score of at least 2 and an H(2)S level as part of the volatile sulfur compounds (VSC) higher than 50 ppb, were divided into four groups. Participants were stratified according to their organoleptic ratings (OR). Group I: mouthrinse I (250 ppm F(-) from amine fluoride/stannous fluoride (ASF), 0.2% zinc lactate, oral malodour counteractives); group II: mouthrinse II (0.05% CHX, 0.05% cetylpyridinium chloride, 0.14% zinc lactate); group III: mouthrinse III (0.12% CHX); group IV: tap water. All groups were instructed to perform standardized oral hygiene measures and to apply the respective test rinse twice daily after tooth brushing. Malodour was assessed by organoleptic measurement and by VSC levels at baseline, day 1, day 7, day 14 and day 21 into the study. To evaluate discolouration of the teeth, the colour was assessed at baseline and final visit. The ASF mouthrinse showed superior efficacy as compared to the negative control. A significant reduction in OR and VSC readings was achieved after single application as well as after 7 and 21 days of continuous use. Between test groups I-III no statistically significant differences were found at any time point. There was also a trend towards fewer side effects caused by the ASF product compared to the products containing CHX. The newly developed mouthrinse product significantly reduces oral malodour in patients with increased values both in OR and in VSC.