Aerosols are an increasingly important mode of delivery of drugs, particularly bronchodilators, for the treatment of respiratory diseases, notably asthma and chronic obstructive pulmonary disease. The most common type of nebuliser is the jet nebuliser (JN); they have been in use for more than a century but these devices can be cumbersome to use and may sometimes deliver insufficient amounts of drug. A more recent development in aerosol therapy is the vibrating mesh nebuliser (VMN) which is very user friendly and is more efficient than the JNs due to an extremely low residual volume. Scintigraphy images from studies of volunteer subjects using radio-labelled aerosol treatment show that VMN-generated aerosols deliver more drug to patients in a shorter period of time than JN-generated aerosols. Various bench, animal model and small clinical studies have shown that VMNs are more efficient than JNs in drug delivery, potentially improving clinical outcomes. These studies have included various breathing circuits used in mechanical ventilation (MV), non-invasive ventilation, high-flow nasal cannula systems and devices for spontaneously breathing patients. The efficiency of drug delivery was affected by factors including the position of the nebuliser in the circuit and humidity. Some studies have shown potential substantial savings by hospitals in the cost of MV treatments after switching from metered dose inhalers to VMNs. VMNs have also been shown to be effective for the administration of inhaled antibiotics, corticosteroids and other drugs. Larger studies of the effects of VMNs on patient outcomes are needed but they are likely to be an increasingly important means of administering therapies to a burgeoning population with respiratory disease.