INTRODUCTION: Preeclampsia is a severe multisystem disorder with unexplained etiology and progressive course that complicates 3-7%of all pregnancies and it is the leading cause of maternal and fetal death. This research is based on the hypothesis that elevated maternal serum copeptin level and decreased serum PP13 level in the first trimester are predictors of the development of preeclampsia. The aim is to find a model for the prediction of preeclampsia in the first trimester using the combination of biological markers and maternal risk factors for preeclampsia. ----- SUBJECTS AND METHODS: A prospective study was conducted at the Department for Gynecology and Obstetrics of the University Hospital Center Zagreb in the period from 2015 to 2019. The study included 400 primiparous women during the first trimester of pregnancy who had risk factors for preeclampsia. RESULTS: Serum level of PP13 ≤ 113 pg / mL in primiparous women in the first trimester of pregnancy predicts the occurrence of preeclampsia with a sensitivity of 90,48 % and a specificity of 64,38 %. Serum copeptin level > 0,37 ng / mL predicts preeclampsia with a sensitivity of 85,71% and a specificity of 77,57 %. Primiparous women older than 35 years with pathological values of PP13 and copeptin have a 17, 8 times higher risk of developing preeclampsia compared to healthy pregnant women. ----- CONCLUSION: Serum levels of PP13 and copeptin in primiparous women who had risk factors for preeclampsia in the first trimester of pregnancy are a predictor for the development of preeclampsia and fetal growth restriction.