The purpose of this open multicentre study was to evaluate prospectively the efficacy and safety of a combination of fluticasone (250 micrograms b.i.d.) and salmeterol (50 micrograms b.i.d.), both given by a metered dose inhaler, in 413 patients (mean age [+/- SEM] 46.9 +/- 0.7 years) suffering from obstructive airways disease (FEV1 % predicted 73 +/- 1.1%) for 10 +/- 0.5 years. 8 weeks of therapy with both drugs improved FEV1 and peak expiratory flow by 24 +/- 3.1% and 27 +/- 2.7%, respectively. Daytime and nocturnal symptoms, rescue beta 2 agonist use, days off work, and symptoms during working hours decreased. Similarly, the quality of sleep improved (p < 0.001, all comparisons to baseline). More than 80% of patients and physicians independently classified the study medication as superior to their previous therapy. Adverse events possibly, likely or definitely related to the study medication were seen in 9% of patients. In conclusion, an inhaled corticosteroid (fluticasone) together with an inhaled long-acting beta 2 agonist (salmeterol) is an effective and well tolerated therapy in patients with obstructive airways disease.