Cutaneous digital blood flow (CDBF) during electrical promontory stimulation was measured by laser Doppler flowmetry in 46 tinnitus patients. In patients with tinnitus suppression. CDBF was increased. In contrast, patients in whom treatment did not suppress tinnitus experienced no change in digital blood flow. The cutaneous digital blood flow of patients who experienced slight relief did not differ significantly from patients who experienced no relief. The ratio of CDBF before and after treatment did not correlate with patient age, audiogram pattern. Our results suggest that relief of tinnitus was closely related to increased parasympathetic nerve tone.