‘Cerebral palsy’ is an emotive term, which to parents often has the same impact as cancer or other dreaded diagnoses. For a child it is a label which can open doors to extra provision in schools and in the community, but which in itself may mean segregation, causing difficulties in participation. For a clinician it can be a diagnostic trap due to the failure to consider other conditions that impair motor function. For both clinicians and researchers it can be difficult to specify. Concerned about limitations of the current concept, a group of selected experts met last year to discuss the definition and classification of cerebral palsy. The preliminary results of their work are printed in this issue (p 571–576), with accompanying invited personal commentaries. We hope that it will provoke vigorous discussion.