Lemierre's syndrome was first described by André Lemierre by studying the association between oropharyngeal infections and thrombosis of the internal jugular vein. The internal jugular vein is located in the parapharyngeal space which is divided in the anterior muscular section and the posterior neurovascular section. The carotid sheath is in the posterior section and an infection from this section may result in thrombophlebitis of the internal jugular vein. The etiology of LS may be different. However, the most common cause is bacterial etiology, with Fusobacterium necrophorum (F.n) being the main causative agent of LS. The primary infectious focii lie in the head and neck region, mainly pharyngitis or tonsillitis. The epidemiological studies of LS are not quite possible because of its rarity, conflicting definitions and multiple titles. The exact anatomical pathway of the responsible pathogen and the predisposing conditions are not well founded. There are possible routes of infection with hematogenic, lymphatic or direct invasion through connective tissue, with primary mucosal damage through which further pathogen production is possible. The clinical picture consists of general and local symptoms. The diagnosis of LS is almost always delayed, and the identification of internal jugular vein thrombosis is the first clear sign. Failure to recognize the symptoms and untimely therapy can lead to complications and death. The therapy can be by antibiotics, anticoagulants, and surgical.