Hypothyroidism may accompany pericardial may accompany pericardial effusion occasionally, in the patient who complains of any symptom of hypothyroidism and dose not receive treatment. We have experienced two cases of hypothyroidism presenting with the symptoms of dyspnea and chest tightness. The cuase of dyspnea and chest tightness was pericardial effusion and congestive heart failure. So we report two cases of primary hypothyroidism presenting with pericardial effusion and review the literature.