Ninety-three patients scheduled for various elective surgical procedures were divided into three equal groups and had induction of anaesthesia with either thiopentone (5 mg/kg), thiopentone (5 mg/kg) plus gallamine (0.3 mg/kg), or with flunitrazepam (0.03 mg/kg). Four minutes after induction they received a bolus intravenous injection of succinylcholine (1 mg/kg). Intra-ocular pressure was measured before and after induction, and approximately 1 minute after succinylcholine. It was found that flunitrazepam prevented the increase in intra-ocular pressure better than thiopentone plus gallamine. In both these groups, the subsequent intravenous administration of succinylcholine slightly increased the pressure but to levels below that noted before anaesthesia was induced. However, intra-ocular pressure was significantly increased above baseline levels when succinylcholine was injected after induction with thiopentone alone. Flunitrazepam is recommended, therefore, as a possible alternative for thiopentone-gallamine induction with succinylcholine when an increase in intra-ocular pressure must be prevented.