Positional head deformities have increased dramatically since introduction of the SIDS-recommendations in the early 1990s. Initially, cosmetical concerns about the head shape are dominating but long-term neurological problems and developmental delay are reported too. Close follow-up after an initial clinical assessment is important. A reliable measuring method (e.g. 3-dimensional laser scan) enables to monitor the progress and to evaluate the influence of physiotherapy. Percentiles are available to grade the severity of head deformities and to identify infants with severe forms, who could benefit from helmet therapy. It is the aim to intervene as soon as possible once a diagnosis is made. Extending the therapy to more than 5 months does not seem to be beneficial. A positive effect is already seen within the first 2 ½ months. Effectiveness of helmet therapy depends on parental compliance. Repeated measurements to visualize even subtle improvements might encourage parents to continue with the helmet therapy for the required time period. In the future, more attention should be paid to the prevention of positional head deformities. On one hand, the SIDS-recommendations could be extended with advice about the importance of nursing infants in a supervised prone position to reduce head deformities. On the other hand, parents of newborns at special risks could be helped with better guidance.