Patients with chronic obstructive pulmonary disease (COPD) are often treated with high dose inhalations of beta 2-agonists. We compared domiciliary therapy with terbutaline administered by the Turbuhaler and by a jet nebulizer. Forty nebulizer users with severe COPD were included in the randomized, double-blind, cross-over study. Terbutaline was inhaled t.i.d. for 2 weeks as dry powder (5 doses = 2.5 mg) by Turbuhaler or as solution (2 ml = 5 mg) by jet nebulizer (Pari Inhalierboy). The mean age of the 25 completing patients was 66 years (range: 54-81), the mean FEV1 was 0.73 l or 29% of predicted (range: 11-55%). The period where the Turbuhaler delivered the active drug was preferred by 16 patients, the nebulizer period by seven (P = 0.09). The median score concerning feeling of control over the disease--according to the Chronic Respiratory Disease Questionnaire--was better after the Turbuhaler period (P = 0.01). Other scores concerning disease related quality of life, the daily peak expiratory flow rates, the additional use of a metered dose inhaler were not significantly different for the two types of treatment. It is concluded that high dose domiciliary terbutaline treatment by Turbuhaler can replace nebulizer treatment in most patients with severe COPD.