Background. Decrease in intraocular pressure (IOP) during pregnancy has been reported by previous studies,but amount of decrease varies from study to study. Moreover,previous studies have concentrated on the last trimester of pregnancy or one reading per trimester. IOP changes throughout the pregnancy have never been described. Therefore,the present study was planned to determine IOP throughout the pregnan cy,after placing control on IOP affecting factors.Subjects and methods. Thirty-six pregnant and same numbers of non-pregnanat women of the same age group were studied. IOP measurements were taken at four week intervals throughout the pregnancy,with the Goldmann applanation tonometer.Results. As compared to control subjects,up to 8th week,IOP remained the same. At 12th week,it becomes significantly lower. The IOP differences between fIrst and second (P<0. 05),and second and third (P<0. 001 ) trimesters of pregnancy were significant. In every subject, IOP decreased during pregnancy.However,there were variations among individuals in the extent of IOP decrease Conclusbos. With advancing pregnancy, intraocular pressure decreases. Knowledge of the normal level of intraocular pressure in various stages of pregnancy may help glaucoma screeners. Background, Decrease in intraocular pressure (IOP) during pregnancy has been reported by previous studies, but amount of decrease varies from study to study. Moreover, past studies have concentrated on the last trimester of pregnancy or one reading per trimester. IOP changes throughout the Pregnant have never been described. Thus, the present study was planned to determine IOP throughout the pregnan cy, after placing control on IOP affecting factors. Subjects and methods. Thirty-six pregnant and the same numbers of non-pregnanat women of the same age group were studied. IOP measurements were taken at four weeks intervals throughout the pregnancy, with the Goldmann applanation tonometer. Results. As compared to control subjects, up to 8th week, IOP remained the same. differences between fIrst and second (P <0. 05), and second and third (P <0. 001) trimesters of pregnancy were significant. In every subject, IOP decreased during pregnancy. How ever, there were variations among individuals in the extent of IOP decrease Conclusbos. With advancing pregnancy, intraocular pressure decreases. Knowledge of the normal level of intraocular pressure in various stages of pregnancy may help glaucoma screeners.