OBJECTIVE: Assessment of patient preferences for attributes of asthma treatments. METHODS: Two hundred ninety-eight patients, aged 18-60, from 15 centres in Sweden completed a questionnaire concerning their asthma and ranked 18 alternative treatments using conjoint analysis. Patients were treated with either inhaled corticosteroids (ICS) or short acting bronchodilator alone (n = 123) or ICS and long acting bronchodilator (separate inhalers n = 87, combination inhaler n = 88). Attributes analysed were: maintenance treatment, additional reliever, time to onset and duration of reliever, number of symptom-free days (SFD) per month, and out-of-pocket cost per month. RESULTS: Conjoint analysis showed that the most important aspect of treatment was SFD. Forty percent of the patients had 15 or less SFD per month. Eighty-five percent of the patients preferred another treatment than their current treatment. Treatment preferences were heterogeneous and in 78% not covered by current treatment guidelines. One of two patients preferred a combination inhaler to separate inhalers, and three of four patients a reliever that is both rapid- and long-acting. The most preferred treatment was a combination inhaler for maintenance and reliever use. On average, the patients were willing to pay SEK 328 (USD $36), additionally to their current expenditure, per month for the change to the preferred treatment. CONCLUSION: Symptom-free days were the most important attribute in asthma treatment. Patients were willing to pay for a switch to their preferred treatment. The most favoured treatments were a reliever therapy that is both rapid- and long acting and a combination inhaler for both maintenance and as needed use.