Introduction: To evaluate supraclavicular scalenectomy +/- cervical rib excision for thoracic outlet syndrome (TOS), employing Disability of Arm, Shoulder, and Hand (DASH) scoring for functional assessment post-decompression. Methods: A QuickDASH score was calculated for each patient using the algorithm: ([sum of responses/n] - 1) x 25, where n = number of completed responses. Nonparametric analysis was employed, with significance defined as P <= .05. Results: Twenty-one patients were treated for TOS by the same surgeon; with 5 bilateral procedures (total = 26 procedures). Median DASH scores pre- and postoperatively were 68.5 and 36.0, respectively (P = .002). Just one reported worsening of symptoms postoperatively. Antecedent trauma and smoking were inversely associated with DASH score postoperatively (P = .005 and P = .005). Postoperative scores were less for patients with vascular symptoms (P = .011); scores did not change significantly for those with neurologic (P = .066) or mixed symptoms (P = .345). Conclusions: This study reconfirmed the value of supraclavicular approach for TOS, with the vast majority reporting subjective improvement.