Objective To investigate the efficacy and safety of nusinersen in patients with spinal muscular atrophy (SMA) complicated by scoliosis. Methods A retrospective analysis was performed on the clinical data of SMA patients with scoliosis who regularly received nusinersen treatment at the Spinal Center of our hospital from January 2022 to June 2024. The data encompassed basic information, surgical history, imaging examinations, etc., collected from the electronic medical record system. During the follow-up period, three scales, namely the Revised Upper Limb Module (RULM) score, the Hammersmith Functional Motor Scale-Expanded (HFMSE), and the Spinal Muscular Atrophy Independence Measure-Upper Limb Module (SMAIS-ULM), were employed to assess the patients. The results of these assessments were compared with pre-treatment baseline data. Results A total of 22 SMA patients were included in the analysis. The median age was 13.2 (9.8-21.8) years, and nearly half of the patients (41%) were unable to sit independently. The median pre-treatment Cobb angle was 101.0 (42.3-121.3) degrees, and 17 of these patients (77.3%) underwent scoliosis correction surgery during follow-up period. The median follow-up duration was 22 (13-26) months. After treatment with nusinersen, the RULM scores of the patients were significantly improved (P<0.001). The motor function of 18 patients (81.8%) showed clinically meaningful improvement. Moreover, the SMAIS-ULM scores of both the patients and their caregivers also increased. During the treatment process, 13 patients (59.1%) reported adverse reactions such as dizziness, nausea, and pain at the site of intrathecal injection. Additionally, 2 patients presented with diarrhea and alopecia. Conclusions Nusinersen has been shown to improve upper limb motor function in SMA patients complicated by scoliosis and enhance their independence in daily activities. This effect appears to be independent of surgical intervention and is associated with a favorable safety profile.