The authors report on their preliminary experience with ultrasound as a screening examination in neonates presenting pilonidal sinuses. Of the 100 patients examined over the 2 previous years, three pathological cases were found (1 tethered cord, 1 lipoma of the filum terminale and one localized hydromelia). Abnormal or doubtful cases were confirmed or further investigated by magnetic resonance. Ultrasound seems to be an accurate technique for the detection of malformation of spinal canal content in neonates under one month of age.