The degree and direction of craniofacial asymmetry in the frontal plane was studied in a sample of 26 shunt-treated hydrocephalic children aged 5 to 18 years. Thirteen of the children had the regulating shunt fixed on the right side of the head and 13 on the left. The shunt had usually been inserted during the first years of life. An age- and sex-matched group of healthy school children and students served as controls for cephalometric assessment by means of linear and angular measurements. Considerable craniofacial asymmetry was found in the shunt-treated hydrocephalic children, the direction of asymmetry being related to the laterality of the regulating shunt device. The most marked asymmetric changes were recorded in the maxillary and mandibular regions, probably due to the adaptive nature of these regions.