Methods. A prospective, placebo-controlled, single-blind study of the effect of gabapentin on tinnitus was employed. Audiograms and personal histories were used to categorize tinnitus etiology as either secondary to acoustic trauma, or not associated with acoustic trauma. Participants were restricted to those with moderate-to-severe tinnitus for at least one year. All participants received gabapentin in a graduated ascending-descending dose series over 20 weeks (peak dose of 2400 mg/day).