The injection treatment of unilateral recurrent vocal cord nerve paralysis, successfully performed 40 years ago with paraffin, has recently been reintroduced with non-reactive synthetics. Improvement in the voice far and above that which can be achieved by voice therapy or any practicable surgical procedure has been demonstrated by several investigators. The technique is relatively simple, and there are no significant untoward reactions. Judging from experimental and clinical studies with these inert materials when introduced into other parts of the body, adverse long range effects are not likely to occur in the larynx. Eleven of 12 patients treated by injection of silicone or Teflon paste had substantial improvement in vocal quality and strength. Silicone was absorbed slowly from the injection site and the improvement was not enduring; when Teflon was used, it stayed at the site and the improvement was sustained.