Treatment of large and/or invasive head and neck cancers results in defects that are complex, such that immediate free tissue transfer provides the best functional outcomes. Consequently, delayed use of free flaps in such patients is seldom seen in today's practice. The purpose of this study was to analyze a recent experience of such delayed microsurgical procedures to evaluate their efficacy and outcomes. Between November 1995 and May 1997, 13 patients underwent free flap reconstruction of residual or secondary defects following initial head and neck cancer ablation. Preoperative status was categorized as open wounds in 8 patients, oral incontinence in 9 patients, poor speech in 5 patients, and difficulty swallowing in 7 patients. Microvascular reconstruction was performed for the mandible and floor of the mouth/chin in 7 patients, cervical esophagus in 2 patients, sinus cavity in 2 patients, and one patient each underwent microvascular reconstruction of the orbit and cranial base. The free flaps utilized were fibular osteocutaneous (N = 6), radial forearm fasciocutaneous (N = 2), rectus abdominis (N = 2), jejunum (N = 1), radial forearm osteocutaneous (N = 1), and serratus (N = 1). There were no flap failures and the overall complication rate was 62%. Functional outcomes were best for the static conditions of open wound and oral incontinence, each demonstrating a 75% and 78% substantial improvement respectively. Conversely, functional improvement in dynamic functions such as poor speech and difficulty swallowing fared less well. Only 60% of patients with poor speech and 14% with difficulty swallowing showed significant improvement despite aggressive speech and swallowing therapy. These data show that the functional outcomes of free flap reconstruction of delayed had and nck cancr complications ar infio to those xpectd ith immediate rconstruction using fre tissue transfer. Neverthlss, reconstruction can be very useful with a hgh likelihod of flap survival and patient improvement.