Cardiac tamponade due to purulent pericarditis with a characteristic greenish fluid is rare in this antibiotic era. It is highly fatal despite early diagnosis and advanced treatment. Gram-positive cocci are the leading cause of purulent pericarditis, which usually results from a direct or hematogenous spread of organisms to the pericardium from the primary foci of infection. We describe an index case of rapidly developing pericardial tamponade caused by oropharyngeal polymicrobial infection in the absence of a primary source of infection in a 62-year-old man, who was successfully managed with emergency large-volume pericardiocentesis followed by pericardiectomy.