Preeclampsia is a major cause of morbidity and mortality in mothers fetuses and neonates worldwide. We conducted a case-control study on 100 preeclamptic women (Case Group) and 100 normotensive pregnant women (Control Group) to investigate that if preconception period of seminal fluid exposure affects the prevalence of preeclampsia in primigravida women. The relation of use of barrier contraceptive method and preeclampsia in primigravida women was significant so that primigravida women using the condom or withdrawal method are in higher risk of being preeclamptic (p = 0.007). There was significant relation between weekly number of coitus before conception and preeclampsia so that the women with more frequent coitus before conception are at lower risk of preeclampsia (p = 0.000). The average age of primigravida preeclamptic women was 24 +or- 3.33 years in comparison with 22.92 +or- 3.80 years in control group. Our data suggest that prevalence of preeclampsia in primigravida women is associated with weekly number of coitus before conception and the use of barrier contraceptive method. (authors)