Recent reviews conclude that there is a need to improve the management of respiratory diseases treated with inhaled drugs, mainly asthma and chronic obstructive pulmonary disease (COPD). Healthcare professionals - mainly in primary care - seem to lack to some degree the evidence-based information required for the selection of the most appropriate respiratory drug delivery devices (inhalers) for the patients, whereas some of the patients often tend to have poor inhaler technique. This could have an impact on the ability to control the respiratory diseases in question. There are probably several reasons for these apparent challenges in the primary care arena. Owing to the abundance of inhalers available at present, especially for the treatment of asthma and COPD, it is quite a challenge to pick the 'right' inhaler for each patient. For an inhaler to be optimal, the patient has to be able to master the inhaler technique required for the specific inhaler. The patient-inhaler interfaces - mouthpieces or facemasks - can add important challenges that further diminish the efficacy of the treatment.