Aims In reirradiation with SBRT for HNC, tumor control must be balanced against toxicity. Higher doses (e.g. 40-45Gy in 5 fractions) to mucosal sites increase toxicity. We evaluated outcomes of 27 Gy in 3 fractions (27Gy/3fx) in patients with recurrent, previously irradiated HNC requiring mucosal reirradiation. Methodology Eligible patients received 27Gy/3fx HN SBRT reirradiation from 2019-2025 for recurrences overlapping mucosa previously irradiated to >50Gy. Endpoints included overall, progression-free, and local failure-free survival (OS, PFS, LFFS). Local recurrences (LR) were classified as in-field (within high dose volume) or marginal (within 2cm). Toxicity was graded per CTCAE v5.0. Multivariable analyses evaluated predictors of outcomes and toxicity. Results 123 patients were included: median age 67, 70% male, 80% squamous cell carcinoma histology. Subsites included oropharynx (39%), oral cavity (34%), nasopharynx (18%), larynx/hypopharynx (24%), and overlapping sites (13%). 41% underwent salvage surgery prior to SBRT (58% with flap), and 72% received systemic therapy. At median follow up 28 months, median PFS, and LFFS were 15 months; median OS was not reached. Two-year OS and PFS and local control rates were 61%, 42% and 49%. Of 46 LR, 78% were in-field, and 22% marginal. Grade ≥3 SBRT-related toxicity occurred in 21%, with SBRT-attributable feeding tube and tracheostomy rates 10% and 3%. Of 17 grade ≥3 hemorrhages, 53% were attributed to SBRT. Larger SBRT volume predicted worse OS, PFS, and LFFS, while ECOG ≥2 predicted worse OS and LFFS. Prior salvage surgery was associated with lower severe toxicity. Conclusion A modest-dose SBRT approach (27Gy/3fx) yielded reasonable outcomes, although most failures were in-field, underscoring the trade-off between tumor control and toxicity. This regimen may offer a toxicity-sparing alternative to higher-dose SBRT in patients requiring mucosal reirradiation and warrants comparative evaluation.