Purpose; Recurrent laryngeal nerve paralysis (RLNP) is often observed in terminal cancer patients. It causes hoarseness of voice, and this interferes with a patient's communication skills. Moreover, RLNP causes aspiration, which decreases the joy of eating, and pneumonia. Although it is important to control the symptoms of RLNP in terminal cancer patients, there are few methods for their control. In this study, 3 terminal cancer patients suffering from RLNP were treated using percutaneous intrafold silicon injection. Methods; The injection was administered under local anesthesia through cricothyroid membrane monitoring fiberscopy. The amount of silicon to be injected was determined on the basis of fiberscopic findings; 0.4 to 2.0 ml of silicon was injected. Results; As a result of this treatment, a marked improvement in voice hoarseness and swallowing ability was observed in all 3 cases. No complications were observed during and after treatment. Conclusion; Thus, percutaneous intrafold silicon injection is a very useful and safe treatment for RLNP in terminal cancer patients.