Objective: The aim of this multicenter study was to evaluate the clinical efficacy of a strontium chloride-containing desensitizer, Hyposen (Lege Artis), over 6 months. Method and Materials: A total of 142 patients with hypersensitivity in 9 dental practices and 2 clinical departments were included in the double-blind, randomized, placebo-controlled study. Each patient exhibited at least 2 hypersensitive and caries-free teeth with exposed dentin surfaces. One tooth was treated with strontium chloride (SR) as recommended by the manufacturer, another with a placebo. Levels of hypersensitivity were assessed after 2, 8, 12, and 24 weeks by cold air and tactile stimuli. After 6 months 132 patients could be reexamined. Results: A reduction of discomfort and pain was observed in 95 patients (72%) after treatment with SR. Statistical analysis showed a significant positive effect of SR compared to the placebo group (P .05, McNemar test). Conclusion: Use of SR for desensitizing hypersensitive dentin is an effective alternative to existing desensitizing agents. Keywords: clinical investigation, dentin, dentin hypersensitivity, desensitizing agents, strontium chloride