A classification of anterior plagiocephaly is proposed by the authors on the basis of the clinical and radiological findings analyzed in a series of 28 subjects less than 1 year old. Three main patterns of the anomaly have been identified. Type I anterior plagiocephaly is characterized by unilateral flattening of the frontal bone and elevation of the superior orbital ridge without deviation of the nasal pyramid. The vomer and petrous bones maintain a normal position. In type II anterior plagiocephaly, the frontal and orbital anomalies are accompanied by contralateral deviation of the nasal pyramid and homolateral anterior displacement of the petrous bone. A deviation of the sphenobasilar bone is associated with the above regard to the anomalies in type III anterior plagiocephaly. The three types of this particular form of craniosynostosis differ with difficulties involved in surgical management and outcome.