History has recorded the antiquity of serious infections in the region of the head and neck. Today, our community still experiences major life-threatening infections in these anatomical locations, which pose significant management difficulties to the oral and maxillofacial surgeon. The aim of this thesis is to review the aetiology, diagnosis and treatment of some bacterial infections involving structures of the head and neck. Such infections may spread, causing serious complications with severe morbidity and occasionally death. This theses deals only with infections of bacterial origin and does not attempt to cover viral, or fungal agents or the chronic specific diseases of tuberculosis and syphilis, and makes no attempt to address the old question of focal infection. The literature review relates especially to Ludwig’s Angina which was first described so dramatically in 1836. To this day it remains as a clinically potentially lethal disease despite the progress of modern medicine. Numerous descriptions in the literature warn of the rapid appearance of symptoms and the danger of respiratory obstruction when management of the airway is not satisfactorily undertaken. Both odontogenic and non-odontogenic causes of orofacial and neck infections are reviewed. Odontogenic problems are given special emphasis as they are now of major concern. The significance of the potential fascial spaces in the face and neck which allow the spread of dental infections is also highlighter. A thorough knowledge of these anatomical relationships is still of the utmost importance to the surgeon if he is to be successful in treatment. The principle of surgical drainage of pus is as important in 1990 as it was 150 years ago. The biological basis for the onset and progress of such fulminating infections in the head and neck region is still poorly understood. One constant need is that the bacteria, both aerobic and anaerobic, be correctly identified. Microbiological techniques are constantly improving and provide an important adjuvant investigation, which then allows the surgeon to provide the most appropriate antimicrobial therapy. Principal to the many aspects of treatment is the ability to maintain the airway of the patient and to provide the depth of anaesthesia necessary to undertake the required surgery. Major bacterial orofacial infections may have severe local and far-reaching systemic effects. Such complications are discussed in all their ramifications. It should be realised that the presentation of these patients at a late stage, when complications have already supervened, may make diagnosis difficult. There is always a necessity to ensure that the underlying cause of the disease is accurately defined and that complication are not allowed to progress further. Finally, a retrospective study of the management of 90 patients with major bacterial orofacial infections who have been treated at Westmead Hospital is presented. The outcome of this study of some major bacterial orofacial infections of the head and neck is the need to stress the importance of urgent surgical management and maintenance of the airway, together with the microbiological determination of the causative organisms and their sensitivities, so that other than empirical antibiotics can be instituted early. This must be combined with an upgrading of the patients’ medical and dental status. It was demonstrated that, in the majority of these patients, ignorance and fear combined with a lack of routine dental care resulted in major infections arising from relatively simple odontogenic causes such as dental caries, periodontal disease and pericoronal infection related to impacted teeth. Without doubt, the immediate care of these patients demanded intensive management. However, it is important to recognise that dental education forms an integral part not only of the recovery programme for the afflicted patient, but also as a community health preventive measure of profound significance.