To investigate the efficacy of radiofrequency thermocoagulation (RFTC) in relieving refractory pain of knee osteoarthritis (OA), we selected 54 patients with chronic knee OA pain, 27 treated with RFTC (case group) and 27 receiving regular treatments (control group). Response evaluations were conducted before treatment, and at the termination of treatment, and 3-month follow-up, applying the visual analog scale, the Medical Outcomes Study 36-Item Short-Form Health Survey (SF-36), and American Knee Society Score (AKSS). Data analyses were performed with SPSS 21.0. At the termination of treatments and 3-month follow-ups, cases gained significantly increased scores in vitality, bodily pain, general health perceptions, physical functioning, and social role functioning by SF-36 scaling and in pain, range of motion, stability, walking, and stair climbing by AKSS (all P < 0.05). Controls received higher scores by AKSS in pain at the termination of treatments and in pain, range of motion, and walking at the termination of 3-month follow-ups (all P < 0.05). Both cases and controls presented significant difference between visual analog scale scores before treatments and those at the termination of 3-month follow-ups (both P < 0.05). All patients felt less pain after treatments, cases presenting better improvement (P < 0.05). Pain was stronger in females compared with males and in a positive correlation with age while had no obvious relation to disease course. In conclusion, RFTC may have better efficacy in relieving refractory pain and promoting function recovery in patients with knee OA than regular treatment.