BACKGROUND: To describe the survival and functional outcomes of salvage surgery for recurrent head and neck squamous cell carcinoma (rHNSCC) after primary radiotherapy. METHODS: A multicentre retrospective observational study of consecutive cases between 1st January 2016 and 31st December 2021. Demographic, tumour details, operative data, and functional and survival outcomes were recorded. Time-to-event outcomes were estimated with Kaplan-Meier curves and Logrank test. Clinicopathological predictors of time-to-event outcomes and 12-month feeding and tracheostomy tubes were evaluated with Cox proportional hazards and logistic regression multivariate analysis. RESULTS: In total, 334 patients were included. Median follow-up was 32.0 months and median age was 63 years old. The most common salvage surgeries were laryngectomy or laryngopharyngectomy (n = 124/332, 37.3%) and open oral or oropharyngeal resection (n = 57/332, 17.2%). Five-year overall survival (OS) was: 42.2% (95% CI 36.5; 48.8%). There was no significant difference across all survival endpoints between rHNSCC subsite, disease free interval, or p16 status. Rates of 12-month feeding tube and tracheostomy use were 22% and 3.1%. Surgical margins were the most consistent prognosticator on multivariate analysis (disease free survival HR 0.49, p < 0.001; disease specific survival HR 0.35, p < 0.001; local control HR 0.49, p < 0.001). Absence of feeding tubes at 12 months (HR 0.49, p = 0.001) was predictive of improved OS. Flap reconstruction (p = 0.006) and oropharyngeal recurrence (p = 0.0002) were associated with 12-month feeding tube use on logistic regression. CONCLUSION: Salvage surgery for rHNSCC has modest 5-year survival, with surgical margins having a considerable influence on outcomes. Following surgery, patients have a high risk of continued functional impairment at 12-months.