Forty-eight patients with severe chronic airways obstruction were given 5 mg terbutaline or placebo from a nebulizer twice daily for 2 + 2 weeks. Twenty three patients preferred terbutaline, 9 placebo and 16 had no preference. The baseline lung function and the 6 minute walking distance were not increased after the terbutaline period. The patients who preferred terbutaline indicated less dyspnoea after the terbutaline period as compared to the placebo period, but did not differ with regard to lung function or walking distance after the terbutaline treatment. The physiology behind the subjective relief from the terbutaline inhalations remains unexplained.