RESUMEN
The objective of this study is to decode the etiopathogenesis, the clinical feature, the diagnosis and the prognosis of the acute mediastinitis resulting of infectious processes of the cephalic segment. Three out of five patients studied presented focus of dental origin and two patients presented focus in the face area. One of them presented Ludwig's Angina before the suppurative process would spread over the mediastinum. In the others, there was fast expansion through the fascial spaces of the neck and, in two of them, besides the mediastinum, there was pleuropericardial involvement. Three patients died due to respiratory insufficiency and two survived with complications. The mediastinitis after cervical suppuration is a special and extremely serious kind of endothoracic infection. The pus reaches that area through the fascial spaces of the neck, taking the organism to an alarming toxemic feature. The rarity of the disease, the little is known about its physiopathology and the initial care of the patient in non-specialized services, which are not familiarized with this type of feature, are factors that can delay the diagnosis and worsen the prognosis