Pulmonary hypertension is a major risk factor in cardiac surgery and has significant impact on morbidity and mortality in the perioperative period. Nitric oxide (NO) is considered to be the gold standard for treatment of pulmonary hypertension in the perioperative setting. The aerosolized administration of the prostacyclin analogue iloprost is a new alternative with similar pulmonary-selective vasodilation and virtually no systemic side-effects. Relevant complications including increased postoperative bleeding have not been observed.