Spina bifida is a common congenital anomaly caused by the incomplete fusion of the caudal neural tube, classified as spina bifida aperta (open) with a visible lesion and spina bifida occulta (closed) without external lesions. Its causes are diverse, including genetic factors, reduced intake of folate and nutrients, maternal obesity, diabetes and certain teratogens. Most cases may be prevented with maternal folic acid supplementation. Closed spinal dysraphism is harder to diagnose due to the lack of evident lesions, but may be suspected in asymptomatic newborns with midline skin signs. The paper describes the case of a newborn presenting with an atypical lumbosacral dimple linked to a lumbosacral vascular malformation. Radiological imaging (US and MRI) facilitated early detection and treatment of the neural tube defect, preventing progressive neurological and orthopaedic damage linked to tethered cord syndrome.