AbstractA clinical study was conducted on four adults to compare the relative efficacy of 0.2% chlorhexidine digluconate and 0.1 % stannous fluoride (SnF2). Using a crossover experimental design, subjects rinsed twice daily for 5 days with SnF2and then, after a 2‐day interim recovery period, for 5 days with chlorhexidine. Statistically significant differences (P<0.05) in the relative efficacy of the two agents were found. Chlorhexidine was more effective in reducing Gingival and Plaque Indices, plaque wet weight and bacterial Colony Forming Units, calculated both per subject and per grou