Surgical treatment for neuromuscular scoliosis is effective for most patients. Although those afflicted constitute a heterogeneous group, the aim of surgical treatment is approximately the same for all patients: a spine balanced in the coronal and sagittal planes over a level pelvis. Surgery results in a more stable and straighter spine, which should in turn improve performance in different activities. Previous evaluations of surgery for neuromuscular scoliosis reported in the literature have focused primarily on Cobb angles; there are very few studies dealing with the ability to perform various activities. A new tool for evaluation was developed in several steps, starting with a telephone interview with patients who had undergone surgery and a literature search. The evaluation instrument was then developed, followed by a pilot study and validation of new parts of the instrument. The instrument focuses on performance components and on activity performance. Eight items are evaluated before and after surgery. These data are complemented by a questionnaire administered to the patient or relatives at follow-up. The new parts of the instrument were developed specifically for patients with neuromuscular scoliosis, and the data obtained have been shown to have a high correlation with established measures of activities of daily living of daily living). They should therefore provide us with useful information concerning functional gains as a result of surgery as well as the effect of surgery on activity performance.