Inhaled corticosteroids (ICSs) are recommended for treatment of persistent asthma. Several ICSs are available and delivered by a variety of devices. After the banning of chlorofluorocarbon (CFC), a formulation of hydrofluoroalkane (HFA)-flunisolide marketed with an in-built spacer has been developed, complying with the request of efficacy and safety for children and adults. It delivers an aerosol with mass median aerodynamic diameter smaller than that of the CFC-formulation (1.2 vs 3.8 m). The extrafine aerosol and the add-on spacer are peculiarities of HFA-flunisolide with respect to the traditional ICSs, assuring larger lung deposition, lower oro-pharyngeal dose and targeting small airways. HFA-flunisolide with the spacer is effective at one-third the dose of CFC-flunisolide delivered without spacer. HFA-flunisolide may be considered an effective alternative to currently available ICSs for asthma management of adult and pediatric patients 6 years of age and older.