Purpose of investigation: Hydatidiform mole (HM) is an abnormal pregnancy characterized by proliferation of cytotrophoblast and syncytiotrophoblast and vesicular swelling of placental villi. The fetus or embryo can be absent or abnormal. HMs can be complete or partial. Case Report: A case of diginyc partial HM at 12 weeks of gestational age was referred to the present center of prenatal diagnosis. The patient showed ovarian hyperstimulation syndrome. At ultrasonography, increased fetal nuchal translucency (NT) with fetal anomaly was evident, without sonographic signs of placental mole. Pregnancy was terminated with legal abortion. Results: Partial HM (PHM) was suspected by ultrasonographic fetal markers with ovarian hyperstimulation syndrome, but the diagnosis was performed only with fluorescent in situ hybridization. In particular fetal NT appeared increased also in diginyc mole. Conclusion: In order to improve the detection rate of PHM, routine histological examinations may be associated to fluorescent in situ hybridization in all cases of fetal anomalies.