A controlled randomised double-blind design was used to study the effect of lignocaine on the pain produced by intravenous injection of propofol. Patients received a 2-ml pretreatment solution with temporary venous occlusion, followed by an induction solution. One hundred and three patients were assigned to one of five groups: saline pretreatment, followed by induction with propofol plus saline 2 ml; lignocaine 20 mg pretreatment, followed by induction with propofol plus saline 2 ml; lignocaine 40 mg pretreatment, followed by induction with propofol plus saline 2 ml; saline pretreatment, followed by induction with propofol plus lignocaine 20 mg; or saline pretreatment, followed by induction with propofol plus lignocaine 40 mg. Pain was reduced significantly in all groups in which lignocaine was used and a dose of 40 mg was more effective than 20 mg. There were no significant differences in the incidence of pain among the groups which received lignocaine as pretreatment and the groups which received lignocaine mixed with propofol. Sixty-eight percent of patients who experienced pain or discomfort recalled it in the postoperative period.