Objectives/Hypothesis: To evaluate head and neck patients undergoing secondary (delayed) free flap reconstructions. Study Design: Retrospective chart review. Methods: Of the 523 free flaps between October 2004 and May 2008, 70 patients underwent 71 secondary free flaps. Outcomes include: hospital stay, complications, flap operative time, enterogastric tube, and tracheostomy requirement. Variables assessed include donor site, indication, prior radiation, and extra-cervical vascular anastomosis. Results: Radial forearm (40.8%) and fibula free flaps (29.6%) were most commonly used. Mean hospital stay was 7.9 days, follow-up 23.5 months, and operative time 323 minutes. Complications occurred in 39.4% in hospital (early) and 31.4% after discharge (late). Many required further surgery (33.8%), tracheostomy at discharge (26.8%), and prolonged enterogastric tube feeding (31%). In-hospital mortality was 1.4%, total flap failure 1.4%, and partial failure 5.6%. The radial forearm required the least operative time (P=.002), and had least tracheostomies at discharge (P=.040). Osteocutaneous fibula took longest (P=.0001), and had the highest tracheostomy rate (P=.047). Early complications were highest with anterolateral thigh flaps (P=.001). Osteoradionecrosis resulted in higher tracheostomy rates at discharge (P=.0001). Osteocutaneous flaps took 111 minutes longer (P=.001), and required more tracheostomies on discharge (P=.031), but with lower fistula rates (P=.046). Previous irradiation and extra-cervical vessels did not significantly impact outcomes. Conclusions: Secondary free flaps are technically feasible for head and neck reconstruction with low mortality and flap failure rates. The extra-cervical and external carotid vessels were equally effective. Patients considering semi-elective free flap reconstruction for osteoradionecrosis should be cautioned about complication rates and tracheostomy retention. © 2009 The American Laryngological, Rhinological and Otological Society, Inc.