The effects of atropine methonitrate and salbutamol delivered by wet nebulisa-tion, separately and in combination, were studied in 22 patients with chronic airways obstruction. Atropine methonitrate 1.5 mg, 3.0 mg and 6.0 mg, salbutamol 2.5 mg, 5.0 mg and 10.0 mg and the intermediate dose of each agent in combination were used. Peak expiratory flow rate (PEFR), forced expiratory volume in 1 s (FEV1.0) and forced vital capacity (FVC) were measured. Improvement in the measured variables was greater after salbutamol, alone or with atropine, up to 3 h after inhalation, after salbutamol with atropine 4 and 6 h after inhalation, and after atropine, alone or with salbutamol, 12 h after inhalation. For all patients together there were no significant differences in the mean maximum PEFR, FEV1.0 or FVC that were achieved following atropine, salbutamol or both together. Salbutamol, 5.0 or 10.0 mg, and atropine methonitrate, 1.5 or 3.0 mg, were maximally effective in most patients and at these doses serious side effects were unusual.