Thirty patients with low-back pain of at least one month's duration were included in a double-blind controlled study with third-party administration and treated with either methylprednisolone acetate mixed with lignocaine or isotonic saline, injected at the site of the iliolumbar ligament. The treatment was evaluated by a visual analogue scale, range of spinal flexion ad modum Wright & Moll and of the patients' self-assessments. In the methylprednisolone group, significant decreases in pain score and in patients' self-assessments were found. The range of spinal flexion did not undergo any significant change. No significant changes were found in the control group. No side effects were observed during the study.