Pericardial effusion is the presence of an abnormal amount of fluid/or an abnormal character to fluid in pericardial space. It is commonly seen as part of multisystem infections, malignancy, renal failure, or autoimmune diseases. When fluid in pericardial effusion is pus, it is called pyopericardium or purulent pericarditis. It is one of the dreaded manifestations of bacterial pericarditis. It can be idiopathic/primary without any underlying cause or secondary to infection elsewhere in the body. Pericardial effusion due to pyopericardium may present with cardiac tamponade with life-threatening hemodynamic compromise. Pyopericardium, if not treated in time, may have a 100% mortality. We hereby report a successfully treated case of primary pyopericardium presented with sepsis and cardiac tamponade with multi-organ failure in an immunocompetent host. To the best of our knowledge, there are no previous case reports from our region on acute pyopericardium with tamponade. A 39-year-old man was brought to the emergency department with complaints of breathlessness and fatigue. Screening echocardiography suggested pericardial effusion with cardiac tamponade. We performed emergency pericardiocentesis with drainage of 500 mL of frank pus from the pericardial space. Culture grew Streptococcus mitis, confirming the diagnosis of acute purulent pericarditis. The patient received intravenous antibiotics and other supportive intensive care. He was later discharged from the intensive care unit (ICU) to the medical ward for further continuation of care. Multidisciplinary team management is of paramount importance for the proper diagnosis and treatment of this disease. The case is highlighted because of its unusual causative organism and near-fatal outcome, especially with late diagnosis and management.