Between 1975 and 1992, 426 children with craniofacial malformations were treated in the Department of Pediatric Neurosurgery at the Hopital des Enfants de la Timone in Marseille. Plagiocephaly was present in 71 (16.6%). The authors present a reproducible analysis of the skull base in plagiocephaly based on these 71 patients. A control group of Mediterranean children (n = 20) was used for comparison. Clinical anthropometric patterns were analyzed in all cases. Comparison with the control group showed a difference only in the nasion-lambda distance. Data obtained from clinical anthropometry were compared for the involved and the uninvolved sides. A three-dimensional reconstruction was possible in 20 cases. The statistical correlation between the basal angles (nasion-pterional, nasion-petrosal, nasion-clino-basion, and zygomatic angles) of the involved and uninvolved sides allows a new nosographic identification of this complex malformation.