OBJECTIVE Degenerative lumbar scoliosis and spinal stenosis are more common in elderly patients. Because of many factors, treatment choices are more complex. To investigate the step treatment strategy of degenerative lumbar scoliosis and spinal stenosis. METHODS Between January 2005 and December 2009, 117 patients with degenerative lumbar scoliosis and spinal stenosis were treated with step treatment methods, including conservative therapy (43 cases), posterior decompression alone (18 cases), posterior short segment fusion (1-2 segments, 41 cases), and posterior long segment fusion (> or = 3 segments, 15 cases). Step treatment options were made according to patient's will, the medical complications, the degree of the symptoms of low back and lower extremity pain, the size of three-dimensional lumbar scoliosis kyphosis rotating deformity, lumbar spine stability (lateral slip, degenerative spondylolysis), and the overall balance of the spine. The visual analogue scale (VAS) score of low back and lower extremity pain, Oswestry disability index (ODI), lumbar lordosis angle, and scoliosis Cobb angle were measured and compared before and after treatments. RESULTS Seventy-two cases were followed up more than 12 months, and there was no death or internal fixation failure in all patients. Of them, 19 patients underwent conservative treatment; the mean follow-up period was 19.3 months (range, 1-5 years); no symptom deterioration was observed; VAS score of low back and lower extremity and ODI were significantly decreased at last follow-up (P < 0.05); and lordosis angle was decreased and scoliosis Cobb angle was increased, but there was no significant difference (P > 0.05). Twelve cases underwent posterior decompression alone; the average follow-up was 36 months (range, 1-5 years); VAS score of lower extremity and ODI were significantly decreased at last follow-up (P < 0.05); and scoliosis Cobb angle was increased and lordosis angle was decreased, but there was no significant difference (P > 0.05). Thirty-one patients underwent posterior short segment fusion; the mean follow-up period was 21.3 months (range, 1-3 years); postoperative hematoma, poor wound healing, cerebrospinal fluid leakage, and superficial infection occurred in 1 case, respectively, and were cured after symptomatic treatment; VAS score of low back and lower extremity and ODI were significantly decreased (P < 0.05); and postoperative lumbar scoliosis Cobb angle and lordosis angle were significantly improved at last follow-up (P < 0.05). Ten patients underwent posterior long segment fusion; the mean follow-up period was 17.1 months (range, 1-3 years); postoperative symptoms worsened in 1 case and was cured after physical therapy and drug treatment for 3 months, and deep infection occurred in 1 case and was cured after debridement and continuous irrigation drainage; VAS score and ODI were significantly decreased (P < 0.05); and postoperative scoliosis Cobb angle and lordosis angle were improved significantly at last follow-up (P < 0.05). CONCLUSIONS The treatment of degenerative lumbar scoliosis and spinal stenosis should be individual and step. Surgery treatment should be rely on decompression while deformity correction subsidiary. Accurate judgment of the responsible segment of symptoms, scoliosis and lordosis can prevent the operation expansion and increase safety of surgery with active control bleeding.