Adult scoliosis is a sideways curvature of the spine causing bilateral lower back pain and paresthesia of the lower limbs. Conservative treatment for scoliosis is primarily performed for youth, but scoliosis can be deteriorating as the patient ages. Rare, severe scoliosis with a Cobb angle over 40 degrees with respiratory difficulties leaves open surgery as the only option. However, surgical treatments often suffer from various complications. This case report presents an elderly woman with severe scoliosis at a Cobb angle of 172°. The patient showed no respiratory difficulties. As the patient refused to receive surgical treatment, conservative care was performed. A series of treatments showed positive outcomes to improve the quality of the patient’s life. Extremely severe scoliosis with a 172° Cobb angle has never been reported in the geriatric population. Our case supports the efficiency of conservative management for such severe scoliosis.