OBJECTIVE: To describe a case report of 4G/4G polymorphism of the plasminogen activator inhibitor-1 (PAI-1) gene as an independent risk factor for placental insufficiency. DESIGN: Case report. SETTING: Department of Public Health, State University of Ceará (UECE), Fortaleza-CE, Brazil. CASE REPORT: Hereditary hypofibrinolysis, which is mediated by 4G/4G homozygosity for the PAI-1 gene, is an independent risk factor for pregnancy complications, probably acting through thrombotic induction of placental insufficiency. We report a case of a low risk pregnancy, which separately presented placental insufficiency and fetal centralization at the beginning of the third trimester, without any other clinical manifestations during pregnancy. However, immediately after childbirth, the patient had a deep vein thrombosis of a lower limb. The anatomopathological examination of the placenta showed old and recent placental infarcts. Homozygosity for the 4G allele of PAI-1 gene was subsequently diagnosed as the sole probable causal factor.