The appearance of right-sided mural infective endocarditis has rarely been reported. Here, we report the case of a 40-year-old male with a history of alcoholic liver disease who presented with a partial loss of consciousness and fever. Chest computed tomography scans showed multiple pulmonary infiltration sites and cavities. A repeat transthoracic echocardiogram detected a vegetation on the right ventricular surface of the interventricular septum middle segment, as well as pericardial effusion. Blood, pericardial fluid, sputum, and scalp effusion cultures were positive for methicillin-sensitive Staphylococcus aureus. We diagnosed the patient with infective mural endocarditis complicated by septic pulmonary embolism, pericardial effusion, and cardiac tamponade. The patient was successfully treated with pericardiocentesis and appropriate antibiotics. Right-sided mural endocarditis complicated by pericardial effusion and cardiac tamponade is an uncommon condition in clinical practice. This case confirms the usefulness of transthoracic echocardiography in the early recognition of primary mural endocarditis and its associated complications.