Furosemide administered through repeated dose inhalation has antiinflammatory effects on the airways. We carried out a study to measure the adjuvant effect of this drug with salbutamol inhalation in asthmatic patients presenting an acute or chronic asthma attack. We studied 50 patients, 25 of whom were given salbutamol (0.5%-1 cc) every 12 h and placebo every 12 h. All patients underwent spirometry on the first day and at the end of the treatment (5 days). Peak flow was recorded twice a day as well as daily diuresis and body weight. Peak flow in the morning increased 13.8 l/min in the group given salbutamol and placebo; in group given furosemide, the increase was 2.2 l/min, with statistically significant differences. Peak flow in the evening showed no sizeable differences. The same was true with spirometric variables (FVC, FEV1 and FEF 25-75), which improved greatly in both groups, but without a considerable difference. Diuresis increased in the group given furosemide (510.80 ml; in the group given placebo the increase was 310.20) without a significant difference. Analysis of body weight showed that in the group given furosemide average weight decreased from 140.4 to 138.5 lbs (52.4 to 51.7 kg); in the group given placebo, it increased from 130.3 to 132.6 lbs (48.6 to 49.5 kg). Statistical analysis was significant. We concluded that administering furosemide by inhalation for 5 days as adjuvant treatment to salbutamol in patients presenting with acute or chronic asthma attack is not superior to treatment using salbutamol and placebo.