This paper reports a pilot study analysing axial rotation in patients with adolescent idiopathic scoliosis using three-dimensional MR. The objective was to define the proportion of segmental axial rotation that occurs due to intravertebral deformity in patients with adolescent idiopathic scoliosis. Ten patients with adolescent idiopathic scoliosis with right thoracic curve (Cobb angle 44° – 78°) selected sequentially from clinic were included in the study. Patients were imaged with a Siemens IT Impact scanner using dual echo steady state gradient echo T2-weighting (TR 30msec/ TE 9/45 msec/ 40°). Three-dimensional volume images of the apical ten vertebrae were obtained in the axial plane and were post-processed through multiplanar reconstruction, allowing axial reconstructions to be obtained in the plane of each endplate. Axial rotation was measured, and an absolute value determined by reference to a neutrally-rotated vertebra. The proportion of intravertebral and intervertebral deformity within each scoliotic curve was subsequently determined. Overall change in observed axial rotation from end vertebra to apical vertebra ranged from 20° to 34°, with a mean of 28°. The mean proportion of axial rotation within the overall scoliotic curve occurring due to intravertebral basis was 34%, with a range of 9% – 76%. It was concluded that a significant but variable amount of the overall scoliotic deformity in patients with adolescent idiopathic scoliosis occurs as a result of intravertebral rotation, contributing over 45% of the total scoliotic axial rotation in half of the patients imaged. This study implies that assessment of axial rotation in the plane of individual endplates with three-dimensional MRI may be a useful means for identifying a subgroup of patients in whom derotational surgery is likely to be of limited benefit.