Glycopyrronium 10 micrograms/kg has been compared with atropine 20 micrograms/kg in a mixture with neostigmine 50 micrograms/kg administered for antagonism of residual nondepolarising neuromuscular block in patients over 65 years of age. The initial peak increase in heart rate was less after glycopyrronium, but there were no differences beyond the first two minutes. The incidence of dysrhythmias was less after glycopyrronium but the difference was not significant. The control of secretions was superior with glycopyrronium. It is suggested that the dosage of anticholinergic agents given with neostigmine could be reduced in elderly patients in comparison to that in younger patients.