Lemierre syndrome is caused by an infection in the oropharyngeal region with subsequent thrombophlebitis in the internal jugular vein. The thrombus from the thrombophlebitis can invade other vital organs, such as liver, lungs, or joints, resulting in secondary infection, which further exacerbates the fatal prognosis of this syndrome. Lemierre syndrome, also called postanginal sepsis or necrobacillosis, was first reported by Dr. Lemierre in 1936. In his report, Lemierre mentioned that out of 20 patients who suffered from this syndrome, only two survived. He also stated that all of the 20 patients complained of infections in the palatine tonsils and developed sepsis and thrombophlebitis in the internal jugular vein. Once called a "forgotten disease," this syndrome showed a very high mortality rate until usage of antibiotics became prevalent. In this case report, the authors present a 71-year-old female patient who suffered from Lemierre syndrome with thrombosis extended to the right sigmoid sinus.