With the introduction of human papillomavirus (HPV) vaccination an evidence base on effective adolescent educational interventions is urgently required. We undertook formative research to develop and evaluate a film on HPV and cervical cancer prevention for school children who will be offered HPV vaccination in the UK. The main outcome measures were the number of children allowed by parents to view the film and children's knowledge. Our results indicated that the film's four key messages were acceptable to parents and largely understood by adolescents but these messages will need reinforcing if the full potential of a prophylactic vaccine is to be realised.