Problem To evaluate the outcome and complications of reirradiation of recurrent head and neck cancer after salvage surgery and microvascular reconstruction. Methods Retrospective Study. Twelve patients underwent salvage surgery with microvascular reconstruction for recurrent or new primary head and neck cancer in a previously irradiated field. Median prior RT dose was 63.0 Gy (range 30.0–72.8). Patients then underwent postoperative reirradiation, receiving a median total cumulative radiation dose of 115.0 Gy. Results Three patients (25%) experienced acute complications (<3 months) during reirradiation that resolved with conservative care. Four patients (33%) developed grade 3 or 4 late reirradiation complications (>3 months). There were no incidences of free flap failure. No patients suffered brain necrosis, spinal cord injury, or carotid rupture. The incidence of soft tissue necrosis and osteoradionecrosis was 8%. There were no treatment-related mortalities. Six patients (50%) are alive without evidence of recurrent disease a median of 40 months after reirradiation (range 4–64 months). Conclusion Free flap reconstruction followed by reirradiation is not associated with an increased risk of perioperative, acute, or late complications. Microvascular free flaps allow for maximal resection and reliable reconstruction of previously irradiated cancers before high dose reirradiation, and may reduce the incidence of severe late complications and treatment related mortality. Significance Reirradiation for recurrent head and neck squamous cell carcinoma remains controversial. However, increasing evidence has demonstrated improved survival and locoregional control with reirradiation at the cost of potentially severe or sometimes fatal radiation toxicity. We hypothesize that using well-vascularized tissue and bone at the time of salvage surgery can reduce the incidence of reirradiation complications. This would allow patients at high risk for recurrence to more safely receive a second course of radiation therapy. To our knowledge this is the first report of the effects of microvascular reconstruction on complications and outcomes of patients undergoing salvage surgery and external beam reirradiation.