A retrospective, comparative study.To compare the results, complications, and costs of preoperative halo-gravity traction in in- and outpatient settings.Surgical management of severe spinal deformities remains complex and controversial. Preoperative halo-gravity traction results in a decreased need for aggressive surgical techniques, lower incidence of intraoperative neurologic complications, and improvement of nutritional parameters and preoperative cardiopulmonary function.Twenty-nine patients younger than 18 years with kyphoscoliosis undergoing preoperative halo-gravity traction were divided into two groups: inpatients (n: 15) and outpatients (n: 14, home care or care at the Foundation). Traction time (weeks), traction weight (kg), radiographic curve correction, complications, and costs were compared. For statistical analysis, t test and odds ratio were calculated with a significance of p < 0.05.Mean traction time was 6 weeks for in- and 4 weeks for outpatients (p = 0.038). Initial traction weight was 6 kg in both groups, while final traction weight was 13 kg for in- and 15 kg for outpatients (p = 0.50). At the end of the traction period, coronal correction was 24° in in- and 28° in outpatients (p = 0.5), while sagittal correction was 27° and 29°, respectively (p = 0.80). Pin loosening was observed in 2 patients in each group, of whom 1 outpatient developed pin-site infection. In each group, one patient developed transient neurologic complications (odds ratio 1.091). Mean treatment cost per patient was 2.8-fold higher in inpatients.Considering complications and costs, our results show that preoperative halo-gravity traction in an outpatient setting is an option to be taken into account.Grade III.