We assessed the value of tocainide in the treatment of tinnitus by performing a double-blind controlled trial in which each of 48 patients with annoying tinnitus received either tocainide HC1 900 mg/day or a placebo. Before the trial, the effect of intravenous lidocaine was evaluated in each patient so that both lidocaine and tocainide could be compared in altering tinnitus. We found that tocainide appeared to have no better effect than the placebo, whereas lidocaine suppressed tinnitus in 81% of the patients treated. The mechanisms of action of both drugs as well as their influence on tinnitus are discussed, as are the side effects of tocainide.