Basicranial changes were studied in a sample of 29 shunt-treated hydrocephalics, aged 7 to 18 years, by analyzing differences in angular relationships between structures seen on roentgenologic cephalograms taken at intervals of about 2 years following initial examination. In addition, the natural head position was recorded in 24 subjects at a follow-up examination. The cranial base among the boys showed increased flexure during the follow-up period. This finding was reflected in a decrease in the angle between the sphenoidal and clival planes and that of the nasion-sella-basion. Head posture, calculated in terms of the craniovertical and cervicohorizontal angles, was more forwardly flexed in the shunt-treated subjects than in the corresponding controls.