The aim of this study was to test the effect of a rinse with 0.05% sodium fluoride and 0.05% chlorhexidine on plaque and gingival inflammation compared with a placebo without these agents. In a double-blind study, 47 adults with > 20 teeth and a CPITN score > 1 but < 4 were randomised into test and control groups. After baseline assessments for plaque, bleeding and stain, teeth were professionally cleaned. Subjects were asked to rinse for 30 s with 10 ml of the respective test or placebo rinse after normal oral hygiene for 8 weeks. 39 subjects completed the study. There was no significant difference in the 2 groups at baseline with respect to either plaque or bleeding scores. After scaling and 8 weeks use of the test rinse, there were significant reductions (p < 0.001) in both plaque and bleeding. The control group showed no significant reduction in plaque scores after 8 weeks, but a significant (p < 0.05) reduction in bleeding. However, this reduction was significantly greater (p < 0.001) in the test group than in the control. The test group had a significantly greater (p < 0.05) stain score than the control at baseline. After scaling and rinsing for 8 weeks, stain scores were lower for both groups compared to baseline but reached significance (p < 0.05) only for the control group. It is concluded that, as an adjunct to normal oral hygiene, the chlorhexidine/fluoride rinse had a significant inhibitory effect on plaque and bleeding but its effect on staining is uncertain.