Stannous fluoride (0.4%) has been incorporated into oral hygiene products to reduce dentinal hypersensitivity since the 1960s. The present study was designed to assess the desensitizing efficacy of a stabilized 0.454% stannous fluoride/sodium hexametaphosphate dentifrice compared to a sodium fluoride control dentifrice. This was a double-blind, parallel-group, randomized clinical trial conducted according to the American Dental Association Guidelines for the Acceptance of Products for the Treatment of Dentinal Hypersensitivity. Seventy-seven subjects who met the entrance criteria were stratified based on age, gender, and air-sensitivity scores and randomly assigned to either the stabilized stannous fluoride/sodium hexametaphosphate dentifrice or the sodium fluoride control dentifrice. Subjects were instructed to brush twice daily for 8 weeks. Oral soft tissue examination and efficacy assessments including tactile (Yeaple probe) and thermal (Schiff Air Index) sensitivity were made at baseline, week 4, and week 8. The mean sensitivity score based on the Schiff Air Index for the experimental group was statistically significantly lower than that of the sodium fluoride control group, at both weeks 4 and 8 (P < .0001). The mean sensitivity score based on the Yeaple Probe Index for the stannous fluoride/sodium hexametaphosphate group was statistically significantly higher, indicating a reduction in sensitivity, than that of the sodium fluoride control group, at both weeks 4 and 8 (P < .0001). The results demonstrate that the stabilized stannous fluoride/sodium hexametaphosphate dentifrice provides clinically and statistically significant reductions in dentinal hypersensitivity when compared to the sodium fluoride control dentifrice.