Subependymal pseudocysts are cerebral cysts found in 5% of all neonates. When they are isolated and typical, they result from persistence of the germinal matrix, have a good prognosis and regress spontaneously within a few months. However, associated anomalies are frequent and in such cases the prognosis is poor. They can be of infectious, vascular, metabolic or chromosomal origin. Subependymal pseudocysts have rarely been described in the antenatal period. We report the prenatal diagnosis of two cases of isolated pseudocysts at 32 and 23 weeks. Both ultrasonography and magnetic resonance imaging assisted in the diagnosis and there was normal postnatal outcome in both cases.