One hundred one referred adult patients (ages 20-63; mean, 36 years) with painful idiopathic scoliosis were evaluated. None had prior surgical treatment. Severity of pain was graded and localized over radiographic deformities in the coronal and sagittal planes. Radiographic changes in primary as well as full and fractional compensatory curves were studied. Degrees of scoliosis, percent correction on side bending, vertebral body rotation at curve apex, spinal balance, and lateral olisthesis in the coronal plane, degenerative disc disease, and other degenerative changes in all curves were measured and graded in both the coronal and sagittal planes. Lordosis and kyphosis were measured on all standing sagittal radiographs. Forty-one patients had pulmonary function studies. Multiple variable statistical analysis (Spearman correlation coefficients) of the data found fractional lumbosacral curves most painful and disabling. Scoliosis greater than 40 degrees and kyphosis greater than 50 degrees correlated with increasing pain and decreasing forced vital capacity. Reduction in forced vital capacity also correlated with curve rigidity. Rotation correlated closely with degrees of scoliosis (r = 0.70; P less than 0.0001) and had the highest correlation with pain (r = 0.59; P less than 0.0001) of all radiographic findings and deformities studied.