Background: Patients with central lumbar spinal stenosis (CLSS) complain of not only the lower leg symptoms but also low back pain (LBP) simultaneously in many cases. Therefore, patients who undergo decompressive surgery expect recovery from LBP as well as lower leg symptoms, and surgeons who perform decompression surgery are making efforts to improve both symptoms. The objective of this study is to investigate whether decompression surgery can improve low back pain and symptoms of lower limb pain in patients with one level central lumbar spinal stenosis.Methods: The present study included 39 patients who had findings of central lumbar spinal stenosis and underwent decompression surgery due to its corresponding claudication and lower leg radiating pain complaints from 2013 to 2018. Their pain (lower leg radiating pain and low back pain) and functional outcomes (Oswestry Disability Index (ODI), Roland–Morris Disability Questionnaire (RMDQ), and Short Form-36 (SF-36)) were evaluated before surgery and 6 and 12 months after surgery.Results: Mean lower leg radiating pain continuously showed statistically significant improvement (p < 0.05, p = 0.003); however, the clinical significance of differences above minimum clinically important difference (MCID) was up to 6 months. Mean low back pain was 4.72 ± 3.40 before surgery, 2.33 ± 2.27 at 6 months after surgery, and 2.21 ± 2.02 at 12 months after surgery, showing statistically and clinically significant improvement (p < 0.05) up to 6 months after surgery, after which there were no findings of improvement. Conclusion: Decompression surgery for patients with central lumbar spinal stenosis showed clinically significant improvements in lower leg radiating pain and low back pain up to 6 months after surgery and continuous improvements in lower leg radiating pain up to 12 months, but there was no continuous improvement in LBP.