Background: To investigate the effect of lumbar and sacroiliac joint (SIJ) manipulation on pain and functional disability in patients with lumbar disc herniation (LDH) concomitant with SIJ hypomobility.Methods: Twenty patients aged between 20 and 50 years with MRI-confirmed LDH who also had SIJ hypomobility participated in the trial in 2010. Patients who had sequestrated disc herniation were excluded. All patients received five sessions of spinal manipulative therapy (SMT) for the SIJ and lumbar spine during a 2-week period. Back and leg pain intensity and functional disability level were measured with a numerical rating scale (NRS) and the Oswestry Disability Index (ODI) at baseline, immediately after the 5th session, and 1 month after baseline.Results: A significantly greater mean improvement in back and leg pain was observed in the 5th sessions and 1 month after SMT. Mean changes in ODI in the 5th session and 1 month after treatment also showed significant improvement. The MCIC for NRS and ODI scores in the present study were considered 20 and 6 points, respectively. Therefore, the mentioned improvements were not clinically significant in the 5th session or at 1-month follow-up.Conclusion: Five sessions of lumbar and SIJ manipulation can potentially improve pain and functional disability in patients with MRI-confirmed LDH and concomitant SIJ hypomobility.