Sacroiliac joint (SIJ) pain is one of the leading causes of mechanical low back pain. Treatment includes conservative methods, surgery, and radiofrequency thermocoagulation (RFTC) as a novel therapeutic approach. Herein, we present a 71-year-old female patient who was first admitted to the outpatient clinic about four years ago. The medical history and physical examination findings were compatible with SIJ pain. After unresponsiveness to previous treatments, the patient successfully underwent ultrasound-guided RFTC using the lateral crest technique. This case report demonstrates, for the first time, the long-term efficacy of ultrasound-guided RFTC using the lateral crest technique in the management of SIJ pain.