Myelomeningocele (MMC) is a severe congenital condition responsible for motor and sensory impairments of the lower limbs, incontinence and cognitive impairment. Its screening, sometimes as early as the first trimester, is one of the major goals of modern prenatal care, supported by the emergence of prenatal surgery that results in a significant improvement in motor function, ambulation and ventriculoperitoneal shunt rate in patients undergoing in-utero surgery. From screening to pre- and post-operative prognostic evaluation, prenatal ultrasound is now an essential tool in the antenatal management of this condition. Using the multi planar and three-dimensional modes, it can be used to assess the vertebral level of MMC, which remains the key antenatal prognostic marker for motor function and ambulation, incontinence and the need for a ventriculo-peritoneal shunt. A careful and systematic ultrasound examination also makes it possible to assess the severity and progression of ventriculomegaly, to search for associated cerebral, spinal cord or vertebral anomalies, or to rule out exclusion criteria for in-utero surgery such as severe kyphosis or serious cortical anomalies. New tools from post-natal evaluation, such as the “metameric” ultrasound assessment of lower limb mobility, appear to be promising either for the initial examination or after in-utero surgery. Ultrasonography, associated with fetal MRI, cytogenetic and next generation sequencing, now allows a highly customized prognostic evaluation of these fetuses affected by MMC and provides the parents with the best possible information on the expected benefits and limitations of fetal surgery.