BACKGROUND: The laparoscopy requires carbon dioxide (CO2) insufflation and Trendelenburg position for operational convenience. However, the above circumstances affect the cardiopulmonary systems significantly and intraocular pressure (IOP) may be also influenced. METHODS: In 27 non-glaucoma patients right and left intraocular pressure (RIOP, LIOP) were measured 5 minutes after induction of general anesthesia (control value), 15 and 30 minutes after CO2 insufflation and endelenburg-lithotomy position. RESULTS: The control values of RIOP and LIOP were 11.3 4.7 mmHg and 11.5 4.7 mmHg respectively. At 15 minutes after CO2 insufflation and Trendelenburg-lithotomy position, they increased to 16.6 5.3 mmHg and 17.0 5.9 mmHg (p<0.05). At 30 minutes, 18.4 3.5 mmHg and 18.2 4.1 mmHg (p<0.05). CONCLUSION: CO2 insufflation and Trendelenburg-lithotomy position increase IOP significantly in non-glaucoma patients during laparoscopy.