This study has compared the efficacy and tolerability of formoterol (FORADIL) dry powder and salbutamol in elderly patients with reversible obstructive airways disease (ROAD). A total of 262 elderly outpatients with clinically stable ROAD participated in a multicentre, double-blind, parallel study. Patients were randomized in equal numbers to receive formoterol 12 micrograms b.i.d. formoterol 24 micrograms b.i.d. or salbutamol 400 micrograms q.i.d. for a 3 month period. All study drugs were inhaled through an Aeroliser device. Daily morning and evening peak expiratory flow (PEF) values, symptom scores and additional bronchodilator use were recorded by the patients throughout the study. Clinic assessment which included spirometry and PEF measurements was made at 4, 8 and 12 weeks. Morning and evening PEF values were significantly higher with both doses of formoterol compared with salbutamol. This difference was statistically significant both for the overall study period and during the week preceding each of the clinic visits (4, 8 and 12 weeks). There was no significant difference for the two doses of formoterol with respect to PEF values. The FEV1 and FVC values between the three treatment groups were similar. The daily use of rescue medication was significantly lower for the formoterol 24 micrograms group compared with the salbutamol group. The percentage of patients rating the therapeutic effect as 'very good' was significantly higher for formoterol: 41% on 12 micrograms; 34% on 24 micrograms; 19% on salbutamol. All treatments were well tolerated. This study demonstrates that formoterol 12 micrograms and 24 micrograms b.i.d. by dry powder inhalation are equally effective and are both significantly superior to salbutamol 400 micrograms q.i.d. in the treatment of ROAD in the elderly.