The inhaled route way, which directly brings an appropriate amount of drug in the right place, is at the present time the recommended route for asthma treatments. The development of spacer devices, easier to use, has reduced the indications of nebulised treatments, but these are still essential in some situations. Nebulisation of short acting beta-2-agonists, which usually requires oxygen administration, is still the first line treatment of a severe acute asthma attack. Ipratropium bromide can be added in the nebulisation, depending on the severity of the attack and the response to beta-2-agonists. Sodium cromoglycate is not used in the prophylactic treatment of childhood asthma any more, but nebulised budesonide is still very useful in moderate to severe persistent asthma in children under 5 years of age, after failure of a treatment with a spacer device. The quality of nebulisation is fully dependent on the equipment used, and on the practical conditions of its realization. It is of most extreme importance to use a compressor/nebulizer couple which is validated for the delivered drug, and that the child breathes, depending on age, via a mouth peace or a facial mask.