Fifty-two patients with chronic low back pain due to moderate-to-advanced intervertebral disc degeneration were randomized to receive intradiscal autologous BM-MSCs (planned n=26) or sham (planned n=26). The primary outcomes were pain (VAS) and disability (ODI). Secondary outcomes included quality of life (SF-36), work ability (WAI), and MRI measures (modified Pfirrmann grade, disc height index [DHI], and T2 mapping). Outcomes were assessed at baseline, 1, 3, and 6 months. Overall, the results showed significant structural gains with BM-MSCs (greater DHI and a transient Pfirrmann improvement) but no superiority over sham for pain, disability, or quality of life by 6 months. In short, intradiscal autologous BM-MSC injection appeared safe and biologically active on MRI, yet it did not confer early clinical advantage over sham.