Pericarditis, a common feature of adult-onset and juvenile-onset Still's disease, is rarely complicated by cardiac tamponade. We report one patient with juvenile-onset and another with adult-onset Still's disease presenting with pericardial tamponade. On the basis of our experience and analysis of literature, we suggest early identification of pericarditis and the life-threatening complication of tamponade, with institution of aggressive intervention with corticosteroids and, if necessary, pericardiocentesis and pericardial window formation. These cases remind physicians about the need to include Still's disease in the differential diagnosis of pericarditis and tamponade and to not neglect the potential of severe systemic inflammation to lead to fatal complications in this group of patients.