IMPORTANCE: External nasal valve dysfunction (ENVD) is a common cause of nasal obstruction. Although many techniques are described to help correct ENVD, evidence of the objective changes in the airway achieved by these interventions is mainly unknown. OBJECTIVE: To document the airway changes in patients with ENVD by comparing subjective and objective measures obtained before and after rhinoplasty. DESIGN, SETTING, AND PARTICIPANTS: Prospective case series with validated subjective and objective outcomes at a tertiary rhinologic center in Sydney, Australia. We included 19 patients with nasal obstruction and clinically diagnosed ENVD from January 2012 to May 2013. INTERVENTIONS: Functional reconstructive rhinoplasty involving lateral crural underlay strut grafts using costal cartilage or lateral crural cephalic turn-in maneuvers performed to correct ENVD. MAIN OUTCOMES AND MEASURES: Objective assessment included nasal peak inspiratory flow, nasal airway resistance, and minimum cross-sectional area. Subjective assessment included a visual analog scale for nasal obstruction, the 22-item Sinonasal Outcome Test, the Nasal Obstruction Symptom Evaluation Scale, and the 36-Item Short Form Health Survey, version 2. A 13-point Likert scale was also used to assess overall function and cosmesis. Objective data and visual analog scale scores were obtained before and after decongestion at baseline and 6 months after surgery. RESULTS: Mean (SD) age of the patients undergoing assessment was 33.3 (12.4) years; 13 patients (68%) were female. Significant improvement was observed in scores for the Sinonasal Outcome Test (mean [SD] change, 0.85 [0.96]), Nasal Obstruction Symptom Evaluation Scale (mean [SD] change, 30.53 [26.14]), and overall function (median [25th-75th percentiles] change, -6.5 [-7.0 to 1.0]) and cosmesis (median [25th-75th percentiles] change, -4.0 [-8.0 to -1.0]) (P < .01). The mean (SD) nasal peak inspiratory flow increased from 102.6 (45.6) to 124.0 (52.9) L/min (P < .01). Median (25th-75th percentiles) nasal airway resistance showed no significant change (from 0.296 [0.237-0.414] to 0.292 [0.267-0.371] Pa/cm3/s; P = .92). The minimum cross-sectional area also showed no significant change (mean [SD], from 1.188 [0.407] to 1.229 [0.336] cm2; P = .69). CONCLUSIONS AND RELEVANCE: Contrary to common belief, successful rhinoplasty had little effect on structural shape or resistance in ENVD, but symptoms improved with changes in collapsibility as defined by the nasal peak inspiratory flow. The need to reconstruct lateral wall support is reinforced by the data presented. LEVEL OF EVIDENCE: 4.