Pulmonary hypertension (PHT) associated with systemic lupus erythematosus (SLE) has a dismal prognosis. Vasodilators and immunosuppressive therapy have been tried over the years with discouraging results. Prostacyclin (PGI2) which has potent vasodilatatory and anti-platelet effects has been demonstrated to significantly decrease pulmonary arterial pressure and pulmonary vascular resistance during acute infusion. Satisfactory response has been reported in SLE patients with PHT treated with short-term intravenous continuous PGI2 infusion. We report here a 48-month experience of the use of monthly low dose infusion of a PGI2 analogue, iloprost, in a SLE patient with pulmonary hypertension in New York Heart Association functional Class III. There was an initial haemodynamic response to an acute infusion of iloprost. Repeated infusions were followed by marked improvement in her functional status and her mean pulmonary arterial pressure dropped from 80 mmHg in the first few months and remained static at around 55 mmHg for the subsequent years.