We present a case of a 16-year-old male with large pericardial effusion due to Hodgkin Lymphoma (HL). Shortly after drainage of pericardial effusion he developed a low cardiac output syndrome which had to be treated with extracorporeal membrane oxygenation (ECMO). This 9-day ECMO support helped the patient to recover his cardiac function, and thereafter a remission of his primary disease was successfully achieved with chemotherapy. It is a matter of discussion whether a large pericardial effusion with moderate symptoms in patients with HL should be evacuated or just observed since the effusion should ameliorate with chemotherapy. But based upon our experience in this case of hemodynamic instability due to a large effusion requiring evacuation, we propose that pericardiocentesis procedure should be performed with caution at a slow drainage rate of 0.5-1 ml/kg/hour with a maximum rate of 50 ml/hour, to help avoid the low cardiac output syndrome in patients with similar disease conditions.