The purpose of this study was to compare effect of treatment with an oral long-acting beta 2-agonist (sustained-release terbutaline, Bricanyl depot), an inhaled steroid (budesonide, Pulmicort), and the combined treatment in patients with nocturnal asthma. Thirty-seven patients completed the study. During a 1-week run-in period with inhaled terbutaline monotherapy, the mean nocturnal asthma score was 1.0 (+/- 0.1) (corresponding to one awakening every night), and the mean overnight fall in peak expiratory flow rate was 27.7% (+/- 2.0). The patients were randomly entered into double-blind, crossover periods of 3 weeks each: (1) sustained-release terbutaline, 10 mg twice daily (b.i.d.), (2) sustained-release terbutaline, 10 mg b.i.d., and two puffs (400 micrograms) of budesonide, b.i.d., and (3) two puffs (400 micrograms) of budesonide, b.i.d. The combined treatment resulted in significantly lower overnight fall in peak expiratory flow rate (6.9% +/- 1.4 compared to 9.4% +/- 2.0 during sustained-release terbutaline and 10.4% +/- 1.9 during budesonide) and less nocturnal awakenings (nocturnal asthma score 0.15 +/- 0.05, 0.43 +/- 0.09, and 0.26 +/- 0.06, respectively) than either single treatment alone (p less than 0.05). The differences between the single treatments were not significant. We thus found that an inhaled steroid is as effective as a long-acting oral beta 2-agonist in controlling nocturnal asthma and that the combination is better. The observed differences were, however, small, and other studies would be required to evaluate the clinical significance of the present finding.