Primary pulmonary hypertension is a rar, incurable, and progressive clinical entity. When associated with pregnancy, the prognosis of primary pulmonary hypertension is worsened with maternal mortality rates of at least 50%. The patient was a 29-year-old mother in her 2nd pregnancy, with previous uncomplicated gestation, 5 years ago. She had been well until the 28th week of present gestation when she was admitted because of increasing dyspnea on exertion. She was a housewife with no remarkable family and past histories. We have experienced a patient with primary pulmonary hypertension in pregnancy. She was treated with an oral calcium-channel blocker and low-molecular-weight heparin and was delivered vaginally with good maternal and fetal outcome. So we report a case of primary pulmonary hypertension associated with pregnancy and review literature.