OBJECTIVE This study aimed to describe the distribution of placental growth factor (PlGF) plasma levels in pregnancies complicated by preeclampsia (PE) according to the gestational age at clinical onset and to assess PlGF's predictive role for maternal complications. METHODS A total of 84 women whose pregnancies were complicated by PE before 37 weeks' gestation were enrolled. According to gestational age at onset, three groups were defined: group I, <28 weeks; group II, 28 to 31(+6) weeks; and group III, 32 to 36(+6) weeks. PlGF plasma levels were measured at diagnosis, and their association with maternal complications was investigated. Plasma PlGF levels below 12 pg/mL were designated as very low. RESULTS PlGF levels were very low in seven (87.5%) of eight women diagnosed before 28 weeks' gestation, 29 (78.4%) of 37 patients diagnosed between 28 and 32 weeks' gestation, and 16 (41%) of 39 cases diagnosed after 32 weeks' gestation. The sensitivity of very low PlGF values for predicting maternal complications was 76.9%, but the false positive rate was 65.5%. Positive and negative predictive values were 34.5% and 76.9%, respectively. CONCLUSION The predictive role of a low PlGF level in predicting maternal complications in very early PE is limited because of both its low specificity and low positive predictive value.