Constrictive pericarditis is a rare, potentially treatable, cause of heart failure with preserved ejection fraction that is characterized by insidious onset, challenging diagnosis and dismal prognosis, even following complete surgical pericardiectomy, particularly in advanced disease stages. In recent years it has been proposed that transient pericardial constriction may occur, with an even rarer frequency, during early phases of acute pericarditis and may resolve following specific treatment without progressing to the chronic, irreversible form. We recently observed two cases of well-documented transient pericardial constriction. In the present work we describe these two cases and provide a review on this rare condition, that, if unrecognized and left untreated, may lead to irreversible constrictive pericarditis.