The effects of muscle relaxants and intravenous anesthetics on intraocular pressure(IOP) were studied in 40 patients ranging in age from 12~63 years and undergoning elective non-ophthalmic surgery. IOP was measured with the PErkins Applanation Tonometer before induction, 1 minute and 2 minutes after intravenous anesthesia, 1 minute after succinylcholine and 1 minute after intubation. The patients were divided into 4 groups: thiopental+succinylcholine+intubation (group A, control group) : pnacuronium pretreatment+thiopental+succinylcholine+intubation (group B): ketamine+succinylcholine+intubation (group C): and, pancuronium+ketamine+succinylcholine+intubation(group D). The results were as follows: 1) In group A, IOP changes following thiopental (5mg/kg) administration showed a highly significant decrease (p<0.01) after 1 minute and significant decrease(p<0.05) after 2 minutes compared with the control value. In group B, IOP changes following thiopental admistration decreased significantly(p<0.05) after 1 minute and 2 minutes compared with the control value. 2) The IOP changes following ketamine(2mg/kg) administration in group C and D showed mild increases or decreases and were not statiscally significant(p>0.05). 3)IOP changes after 1 minute following succinylcholine(1mg/kg) administration showed significant increases(p<0.05) in group A, C and highly significant increases(p<0.01) in group D. IOP changes after 1 minute of endotracheal intubation showed highly significant increases (p<0.01) compared with the control value in group A, C and D. 4) Pretreatment with a mondepolarizing muscle reaxant could not prevent the increase in IOP following succinylcholine administration.