This review describes the microbiology, diagnosis and management of deep facial infections and Lemierre syndrome. The origins of most of these infections are odontogenic infections that spread to fascial spaces of the lower head and upper neck. Other sources include pharyngotonsillar, nasal, otologic, salivary gland and dermatologic infections, hematogenic spread, cervical adenitis and trauma. These space infections can be divided into those around the face (masticatory, buccal, canine and parotid), the suprahyoid area (submandibular, sublingual and lateral pharyngeal) and the infrahyoid region or lateral neck (retropharyngeal and pretracheal spaces). The organisms accounting for these infections are aerobic and anaerobic that arise from the oropharyngeal flora. Complications of these infections can be life threatening and can result from hematogenic or direct spread. Complications that arise following local extension include suppurative jugular thrombophlebitis, cavernous sinus thrombosis, carotid erosion, maxillary sinusitis and osteomyelitis of the jaws. Management includes surgical drainage and antimicrobial therapy.