Encephalocele is a neural tube defect characterized by sac-like protrusions of the brain and the covering membranes through an opening in the skull. Encephalocele is less common than other neural tube defects. In this case we presented a 21 years old 20 weeks pregnant woman with fetal occipital encephalocele accompanying lemon sign, normal posterior fossa imaging and normal level of maternal serum alpha-fetoprotein (MSAFP).