Inhaled iloprost is a well-established medication to treat pulmonary arterial hypertension (PAH), a serious and potentially fatal disease of the pulmonary resistance vessels. The therapeutic administration of iloprost requires six to nine inhalations per day, due to the short biological half-life of this prostacyclin analogue. The I-Neb TM AAD TM, introduced in 2006, is the most commonly used nebulizer for delivering iloprost, requiring at least 6.5 min for an inhaled dose of 5 µg. In order to reduce inhalation time, a portable nebulizer based on modern-device technology was developed. The acute safety and tolerability of rapid iloprost inhalation via the BREELIB TM nebulizer was assessed in a four-part clinical trial. In this review, I describe the rationale and features of the new nebulizer, with particular emphasis on the safety and tolerability profile of iloprost inhalation via BREELIB TM observed in the first clinical studies. Meanwhile, the BREELIB TM nebulizer is approved and available for inhaled iloprost therapy combining significantly reduced inhalation time with good tolerability. This new approach will certainly improve patient convenience and compliance, possibly resulting in broader acceptance and improved efficacy of iloprost aerosol therapy in PAH.