A randomized clinical trial of rotational manipulation was conducted on 95 patients with low back pain selected for (1) the absence of any contraindications for vertebral manipulation, (2) the absence of any psychosocial problems that might affect the outcome of treatment, (3) the absence of any previous experience with manipulative therapy, and (4) the presence of palpatory cues indicating that manipulation might be successful. Patients were randomly assigned to one of two groups: an experimental group receiving manipulation therapy and a control group receiving soft-tissue massage. Comparison of the two groups indicated that (1) patients who received manipulative treatment were much more likely to report immediate relief after the first treatment, and (2) at discharge, there was no significant difference between the two groups because both showed substantial improvement.