Appetite suppressants, including aminorex and fenfluramine, have been associated with pulmonary hypertension ever since the well-known outbreak of primary pulmonary hypertension in Europe after treatment with aminorex. The usage of a new anorectic agent, dexfenfluramine, has recently increased dramatically in developed countries. We report 2 new cases of lethal pulmonary hypertension associated with the use of dexfenfluramine.