We report the prenatal findings of cystic hygroma. Nuchal cystic hygromas are characterized by single or multiple congenital cystics of the lymphatic system, most found within the soft tissues of the neck. Embriology are the clinical consequence of a delay or absence of the communications that normally develop between the jugular lymph sacs and the internal jugular veins; the obstucted jugular lymph sacs dilate along the paths of least resistence into the posterior and lateral cervical areas. A 26-year-old woman, gravida 1, was referred at 24 weeks gestation to our department from another hospital where sonographic diagnosis of neck masses had been made. Twoand three-dimensional sonographic confirmed the presence of a large cystic areas with septa termed cystic hygroma develop within the skin in the right lateral aspect of the neck, without other malformations. Examination in utero using Magnetic resonance imaging (MRI) had been made to study this case.