Aerosolized terbutaline sulfate at a dose of 0.50 mg has been shown to produce significant bronchodilation in patients with reversible airway disease. The purpose of this study was to evaluate the safety and efficacy of 0.50 mg terbutaline aerosol used on a regular dosage schedule over a six-week period. Sixteen ambulant patients with chronic obstructive pulmonary disease with a component of reversible airway disease were evaluated. The patients were tested at two-week intervals during a six-week period. The patients abstained from all bronchodilatory medications for at least 10 hours prior to the time of evaluation. The evaluation consisted of baseline pulmonary function tests, ECG, CBC, urinalysis, and renal and liver function tests. After the terbutaline was administered, a rhythm strip and pulmonary function tests were repeated at 5, 15, 30, 60, 120, and 180 minutes. Throughout the six-week study, there was a statistically significant increase in FEV1.0 and MMEFR (P less than 0.001): deltaFEV1.0 (ml) 740 (63%) 550 (45%) 340 (25%) 320 (25%) deltaMMEFR (liters/min) 42 (74%) 29 (46%) 28 (43%) 36 (42%). No abnormal laboratory results or paradoxical bronchospasm were noted during the study period; however, sympathomimetic side effects were observed. Aerosolized terbutaline sulfate (0.50 mg) when used on a regular schedule over a six-week period is effective in the treatment of reversible airway disease.