The objective of this study was o determine the efficacy of a newly developed pneumatic orthotic cranial molding helmet for correcting positional plagiocephaly. The design was retrospective and the setting was a tertiary care center. Subjects were all patients in whom positional plagiocephaly has been diagnosed and who have been fitted by the Orthotics and Prosthetics Department for the helmet. Diagonal cranial lengths and widths were measured at each visit. Analysis included the calculation of the ratio change in oblique diameters compared with time, patient's age, and head circumference. Seventy-five patients met inclusion criteria (50 boys, 25 girls). Patients with pneumatic orthotic cranial molding helmet therapy had significantly improved outcomes as compared with pretreatment measurements (P < or = 0.0001). The helmet did not limit cranial growth as evidenced by significant normalization of the oblique measurement ratio when compared with increasing cranial circumference and age (P = 0.0003, P < or = 0.0001, respectively). The pneumatic orthotic cranial molding helmet successfully corrects positional plagiocephaly and does not hinder cranial growth.