The effectiveness of spinal manipulative therapy for low back pain is compared between two groups of patients: a small group (25) of patients with lumbar spondylolisthesis and a larger group (260) of patients without spondylolisthesis. This data, which was collected from a previously published study on the effectiveness of manipulation for chronic low back pain, shows that the results of manipulative treatment are not significantly different in those patients with or without lumbar spondylolisthesis.