Abscesses and deep space infections of the head and neck continue to be encountered in clinical practice. Recognition of these processes requires careful physical examination, an adequate index of suspicion, and appropriate application of modern imaging techniques. The principles of management of abscesses are largely unchanged. Space infections must be drained. A specimen should always be submitted for bacteriologic evaluation to allow change in antimicrobial administration when patterns of resistance are identified. Fungal infection should be considered when rhinosinusitis develops in the hospitalized immunocompromised patient. Biopsy of abnormal tissue is the mainstay of diagnosis under these circumstances. Therapy frequently requires surgical debridement in addition to administration of antifungal chemotherapy.