The incidence of trigeminal neuralgia (TN) in elderly patients is higher. However, for those with poor fitness, the optimal surgical treatment for those refractory to medical treatment is controversial. The aim of current study was to investigate the long-term outcome of computed tomography (CT)–guided percutaneous radiofrequency thermocoagulation (PRT) for 304 TN patients 70 years or older. We conducted a retrospective study of 304 elderly patients with TN who were treated with CT-guided PRT between 2002 and 2012. Follow-up was censored at the time of last contact, additional surgery, or death. Sixty-seven patients (22.1%) were of more than American Society of Anesthesiologists classification system physical status II. Excellent pain relief was 100% at discharge, 85% at 1 year, 75% at 3 years, 71% at 5 years, and 49% at 10 years. Pain relief outcomes were correlated with facial numbness. Lower temperature group (≤75°C) can attain the same long-term pain relief as higher temperature group (≥80°C); however, the incidence of painful dysesthesia rate of higher temperature group was higher than lower temperature group. Postoperative morbidity included facial numbness, masseter weakness, corneitis, hearing loss, dropping eyelid, and limited mouth opening. There were no mortalities observed during or after PRT. Our result showed CT-guided PRT is safe and effective for classic TN patients 70 years or older, including poor-fitness patients (American Society of Anesthesiologists classification system physical status >II). Lower temperature (≤75°C) is recommended for PRT in the treatment of TN.