Asthma in younger children appears to be increasing in prevalence, whilst at the same time it is recognized that inhaled corticosteroids and bronchodilators are the mainstay of treatment for this condition. Presently the devices available for aerosol treatment of young children are mostly developed for use in older children and adults. However, an awareness of the need for delivery systems dedicated to use by young children is increasing. The devices available at present for aerosol treatment of young children comprises the nebulizer, metered-dose inhaler with spacer, and dry powder inhaler. The inhaler strategy found most useful at present can be summarized as follows: children younger than 2 years can use MDI+spacer+mask or nebulization, while children above 2 years can use MDI+spacer (without mask). Older children (3-4 years) can be easily taught the use of a Rotahaler.