A total of 105 infants with nonsynostotic posterior plagiocephaly were treated using a helmet or by head positioning. Effect of treatment was scored using a cosmetic outcome score (0-10 points) assigned by the parents. The onset of the observed skull deformity correction was not different for the helmet vs. nonhelmet treatment. Improvement was significantly better and faster in the helmet group compared with nonhelmet treatment (p < 0.01 and p < 0.001, respectively).