There are several devices known as spacers and aerochambers designed to help in the administration of drugs in spray into pulmonary airways in asthmatic patients. This study was done to determine the effect on FEV1 of salbutamol given through an aerochamber compared with metered dose inhaler and spacer. Thirteen asthmatic patients who met all selection criteria proposed, were included. Spirometry was operformed before and after salbutamol application by means of one of the aforementioned devices, assigned at random. The effect on FEV1 with metered dose inhaler was 22.76%, with spacer it was of 23.35% and with aerochamber it was of 23.94%. Statistical analysis did not show significant differences among groups. These data suggest that each of the three devices tested have the same effectiveness for administration of salbutamol in spray. This is, however, a preliminary study.