BACKGROUND: During ophthalmologic surgery, a variety of anesthetic induction techniques are used in an attempt to prevent the rise of intraocular pressure (IOP). This study compared the effects of etomidate, a new intravenous anesthetic agent, on the changes in IOP with those of thiopental sodium and propofol. METHODS: Forty-five patients were randomly allocated and divided into three groups to be injected intravenously with etomidate 0.2-0.3 mg/kg (E-group, n = 15), propofol 2-3 mg/kg (P-group, n = 15) or thiopental sodium 4-5 mg/kg (T-group, n = 15). Systolic arterial pressure (SAP), heart rate (HR) and intraocular pressure (IOP) were measured at 1, 2 and 3 minutes after the administration of the induction agents. During the induction of anesthesia, the incidence of IV injection pain, myoclonus, hiccup and a decrease in SAP of more than 30% were investigated. RESULTS: At 1, 2 and 3 min following the induction of anesthesia, the SAP in the P-Group decreased significantly more than that in the other two groups (P < 0.05). After the induction, heart rate in the T-Group increased significantly more than that in the other two groups (P < 0.05). The three intravenous agents induced a significant decrease in IOP after an injection (P < 0.05). Comparing the three groups, the IOP in the E- and P-Group decreased significantly more than that in the T-Group (P < 0.05). CONCLUSIONS: Etomidate may be used as a choice of intravenous induction agent to reduce intraocular pressure in ophthalmologic operations especially in an emergency situation, geriatric and hypovolemic patients.