OBJECTIVES: This study aimed at assessing patient preferences for different characteristics of Dry Powder Inhalers (DPIs) from patients with asthma and chronic obstructive pulmonary (COPD) disease in France. METHODS: Attributes characterizing DPIs and attribute levels were defined using focus groups among asthma and COPD patients and interviews of health care professionals, previously reported. Those attributes were ease of use, accurate and easy-to-read dose counter, dose confirmation, hygiene of the mouthpiece, flexibility of device handling and use with breathing difficulties. A survey was conducted among asthma and COPD patients to elicit patients’ preferences and willingness to pay using the discrete choice experiment (DCE) method. A fractional factorial design including 3 sets of 12 choices was created. Each choice was made in two steps: a choice between two fictitious inhalers then between preferred inhaler and current inhaler. Analyses were performed using a ranked ordered logit model. Interactions between attributes and asthma/COPD were tested. RESULTS: Participants included 201 patients with asthma and 60 with COPD. Asthma patients were on average 40 years old and COPD patients were 51 year old. Patients were willing to pay €4.70 per month (standard error: €0.49) for an inhaler requiring one step to prepare a dose instead of four, €3.62 (€0.61) for an accurate dose counter compared to a less precise one, €3.27 (€0.48) for an inhaler giving confirmation that the dose has been taken, €1.02 (€0.38) for flexibility of handling and €4.79 (€0.73) to be able to use the inhaler in case of breathing difficulties. Preferences of patients with asthma and COPD are largely similar. CONCLUSIONS: Patients with asthma and COPD place highest values on the ease of use and ability to use the inhaler in case of breathing difficulties, followed by features giving patients the reassurance about taken dose – precise dose counter and confirmation mechanism.