We describe an adult patient who presented with purulent pericarditis (PP) in whom two-dimensional transthoracic echocardiography demonstrated a marked decrease in the area of the right ventricular (RV) wall together with the overlying fibrin following intrapericardial administration of a fibrinolytic agent. Documentation of this decrease by measurements performed and illustrated on two-dimensional images has not been reported previously in an adult patient with PP, to the best of our knowledge.