Plagiocephaly is a term commonly used to describe congenital forehead asymmetry. Sixty patients with frontal plagiocephaly were evaluated retrospectively and separated into three types: synostotic (N = 24), compensational (N = 3), and deformational (N = 33). Categorization of frontal plagiocephaly as synostotic or deformational was reliably made by physical examination, focusing on the supraorbital rims, nasal root, ears, and malar eminences. Other anatomic parameters useful in the differential diagnosis included chin point, palpebral fissures, and facial height. This study documented that birth histories were similar for synostotic and deformational frontal plagiocephalic infants. However, other deformational anomalies were more common in deformational frontal plagiocephalic infants, whereas malformations had an equal incidence in deformational and synostotic frontal plagiocephalic infants. Torticollis was an associated finding in 64 percent of infants with deformational frontal plagiocephaly; almost all were ipsilateral. In contrast, head tilt, usually to the contralateral side, was noted in 14 percent of patients with synostotic frontal plagiocephaly. Female preponderance was noted in both synostotic (79 percent) and deformational (76 percent) frontal plagiocephaly. Left-sided involvement was seen in 73 percent of patients with deformational frontal plagiocephaly and in 46 percent of patients with synostotic frontal plagiocephaly. Premature pelvic descent, in the left occipital anterior position, may account for the high incidence of left-sided deformational plagiocephaly and ipsilateral torticollis.