Foetal acalvaria is an extremely rare congenital abnormality characterized by the complete or partial absence of skull bones with complete but abnormal development of the brain. A 27 year old multiparous woman was found to have an anencephalic foetus at 12 weeks of gestation. Foetal ultrasound scan at 36 weeks revealed a well formed brain without a cranium. The baby was delivered by cesarean section. The brain was displaced posteriorly due to the absence of supporting skull bones and was covered by a thick membrane. The neonate expired few hours after delivery. Identification of acalvaria antenatally allows the clinician to plan an appropriate timely management.