Background: Spring-assisted surgery is an accepted alternative to cranial vault remodeling for treatment of sagittal craniosynostosis. The long-term safety and efficacy profiles of spring-assisted surgery have not been established. Methods: This study is a retrospective examination of all patients treated with spring-assisted surgery (n = 175) or cranial vault remodeling (n = 50) for sagittal craniosynostosis at the authors’ institution from 2003 to 2017. Data collected included demographic and operative parameters, preoperative and postoperative Cephalic Indices, and complications. Whitaker grades were assigned blindly by a craniofacial surgeon not involved in patients’ care. Results: The mean age at surgery was significantly lower for the spring-assisted surgery group compared with the cranial vault remodeling group (4.6 months versus 22.2 months; p < 0.001). Even when combining spring placement with spring removal operations, total surgical time (71.1 minutes versus 173.5 minutes), blood loss (25.0 ml versus 111.2 ml), and hospital stays (41.5 hours versus 90.0 hours) were significantly lower for the spring-assisted surgery cohort versus the cranial vault remodeling group (p < 0.001 for all). There were no differences in infection, reoperation rate, or headaches between the groups. The percentage improvement in Cephalic Index was not significantly different at 1 (p = 0.13), 2 (p = 0.99), and 6 (p = 0.86) years postoperatively. At 12 years postoperatively, the spring-assisted surgery group had persistently improved Cephalic Index (75.7 preoperatively versus 70.7 preoperatively). Those undergoing spring-assisted surgery had significantly better Whitaker scores, indicating less need for revision surgery, compared with the cranial vault remodeling group (p = 0.006). Conclusion: Compared with the authors’ cranial vault remodeling technique, spring-assisted surgery requires less operating room time and is associated with less blood loss, but it has equivalent long-term Cephalic Indices and subjectively better shape outcomes. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, III.