Tonsillitis is a condition involving the infection of the lymphoid tissue of the tonsils. This pathology of the tonsils is frequently reported as a childhood illness in children of school-going age. The leading causative agent which is associated with tonsillitis is Group A and B Haemolytic Streptococcus and Staphylococcus and Haemophilus influenzae. With rapid and correct treatment and management with antibiotics and analgesics, it can be resolved, and the patient can be free of the symptoms such as sore throat, dysphagia, pain over the throat, and fever. Though in the minority of cases the diseases can progress and can result in multiple complications which sometimes can be lethal and extremely serious. These can be rheumatic fever, acute glomerulonephritis, or tonsillar cyst. One of the sporadic but equally important and grave syndromes is Lemierre's syndrome, which unfortunately has been labelled as a forgotten disease due to the development of antibiotic therapy and management of the disease. The mortality of the disease was extremely high in the pre-antibiotic era. This disease presents the following findings, such as thrombophlebitis of the internal jugular vein, which usually occurs after the presentation of pharyngeal infection. Which in later stages also gives rise to thrombi that advance and extend throughout the body, in the form of septic emboli. The important microorganism which is isolated and associated with the Lemierre's is Fusobacterium necrophorum, a strict gram-negative anaerobe. This article emphasizes and discusses the pathophysiology, and microbiology of Lemierre's syndrome. It also focuses on the clinical symptoms that include the appropriate and timely diagnosis and treatment of this deadly and fatal syndrome, together with the complications that arise with Lemierre's syndrome as the presenting problem.