Objective: Preeclampsia is defined by the new onset of elevated blood pressure and protienuria after 20 weeks of gestation. Protienuria is one of the essential criteria for the clinical definition of preeclampsia. The authors investigated the predictive value of proteinuria in the outcome of pregnancies with preeclampsia. Materials and Methods: In this retrospective cohort study, they entered all pregnant women who were admitted with diagnosis of preeclampsia in Yahyanejad Hospital from 1998 to 2008. Patients’ data such as age, gestational age, level of 24-hour urine protein, liver enzyme, blood urea nitrogen (BUN), creatinine, and other laboratory test. Also, prenatal and maternal outcome were studied. The data analyzed and compare with each other. Results: Out of 289 patients, 5.9% (17) women had placental abruption, 13.1 % (28) patients had intrauterine growth retardation (IUGR), 32.2% (96) had respiratory distress, and 26.6% (77) of the patients’ infants were transferred to neonatal intensive care unit (NICU). Although the present study showed proteinurea cannot be a sufficient predictor for adverse consequences of preeclampsia, however, the incidence of pregnancy adverse effects increased in the patients with elevated 24-hour proteinuria. Conclusion: The authors concluded that proteinuria in patients with preeclampsia is associated with adverse outcome in pregnancy, although it is not an adequate predictor.