OBJECTIVES: A new dry-powder inhaler combination for the treatment of asthma has appeared. The objective of the present study is to analyze the cost impact of the introduction of the new dry-powder inhaler (DPI) –beclomethasone dipropionate with formoterol combination (BEC/FOR) - in the treatment of the moderate to severe persistent asthma METHODS: A mathematical model was designed to estimate the financial impact of the partial substitution of DPI budesonide with formoterol (BUD/FOR) and DPI fluticasone propionate with salmeterol (FLU/SAL). Only direct healthcare costs were considered because the perspective of Spanish National Health Service (NHS) was adopted. The time horizon was four years RESULTS: The prevalence is 4.6% and it increases 0.26% yearly. Current annual total cost of treatment with BUD/FOR and FLU/SAL is estimated in around 512; 538; 565 and 591 million € for 2013-2017 respectively. The new total cost is estimated in about 511; 537; 562 and 587 million € with the introduction of BEC/FOR. The major determinants of costs were the exacerbations of asthma (44.5% of total cost), and the antiasthmatic drugs (40.2%). The pharmacological cost of BEC/FOR represented the 37.02% of the total of this option while those of FLU/SAL and BUD/FOR were the 39.75% and 41.27%, respectively. Finally, the introduction of BEC/FOR (share of 2; 4; 9 and 14% for 2013-2017) was associated with a roughly saving of 0.7; 1.2; 2.8 and 4.5 million € in the same time CONCLUSIONS: The utilization of beclomethasone dipropionate and formoterol in substitution of fluticasone and salmeterol, and budesonide and salmeterol, all of them as dry-powder inhaled, results in important savings of costs for the NHS