Background: The National Healthy School Programme (NHSP) was created in 1999, following ‘Every Child Matters’ to improve personal, social and health education, healthy eating, physical well‐being and emotional health (Healthy Schools, 2007). Schools provide an ideal setting to instil knowledge (DH and DCSF, 2008), comprising an important first step towards behaviour change of dietary habits and thus the prevention of obesity. Previous research into the nutritional knowledge of 11–12 year olds demonstrated that nutrition should have a definite place in the curriculum (Frobisher et al., 2005). The effect of the NHSP status on nutritional knowledge has not yet been investigated. This study aimed to evaluate the nutritional knowledge of 11–12 year olds in a secondary school with National Healthy School Status (NHSS) in 2002 (School A) and in a school working towards gaining the status (School B).Methods: A previously validated questionnaire (Frobisher and Maxwell, 2001) was completed by pupils to test theoretical and practical nutritional knowledge, as well as how they rated their own knowledge of a healthy diet. A semi‐structured interview was carried out with key informants from each school who had a role within the NHSP, in order to investigate their whole school policy, and their involvement and opinions on the benefits and drawbacks to the programme. Subjects comprised 99 pupils from School A and 128 from School B. Mean scores were calculated for each school for total, theoretical and practical areas. Chi‐square tests and t‐tests were carried out using SPSS, version 15.0 (SPSS Inc., Chicago, IL, USA) to compare the differences in knowledge levels between the schools; statistical significance was set at P < 0.05.Results: School A pupils’ average total, theoretical and practical nutritional knowledge scores were 72%, 60% and 78%, respectively. These were significantly higher (P < 0.01) than the scores of pupils from School B (60%, 52% and 64%). School A pupils rated their knowledge as seven out of 10, which is significantly higher than School B (6.4; P < 0.05). Pupils at both schools showed good knowledge of sugar being linked to tooth decay, milk being good for bones, and eating fruit and vegetables as comprising part of a healthy diet.Discussion: Results of this study suggest that pupils attending a secondary school with the NHSS have greater nutritional knowledge. This is of benefit because an association has been observed between having good nutritional knowledge and consuming a healthy diet (Wardle et al., 2000). Furthermore, these pupils have increased confidence in their ability to ascertain what is healthy. Improved nutritional knowledge and confidence together may aid health behaviour change and instil healthy dietary habits for adulthood. This in turn may slow the progression of the obesity epidemic.Conclusions: This present study has demonstrated an improvement in nutritional knowledge and confidence in pupils who attend a school implementing the NHSP. Pupils’ knowledge may be affected by other factors (e.g. socioeconomic status). A limitation of this study is that socioeconomic status was not assessed.References Healthy Schools (2007) National Healthy Schools Programme Progress Report. Available at http://www.healthyschools.gov.uk/ProgressReports.aspx (accessed on 12 November 2007).Department of Health and the Department for Children, Schools and Families (2008) Healthy Weight, Healthy Lives: A Cross‐Government Strategy for England. Available at http://www.dh.gov.uk/en/Publicationsandstatistics/Publications/PublicationsPolicyAndGuidance/DH_082378 (accessed on 6 May 2008).Frobisher, C., Jepson, M. & Maxwell, S.M. (2005) The attitudes and nutritional knowledge of 11‐ to 12 year‐olds in Merseyside and Northern Ireland. Int. J. Consum. Stud.29, 200–207.Frobisher, C. & Maxwell, S.M. (2001) The attitudes and nutritional knowledge of a group of 11–12 year olds in Merseyside. Int. J. Health Promot. Educ. 39, 121–127.Wardle, J., Parmenter, K. & Waller, J. (2000) Nutrition knowledge and food intake. Appetite34, 269–275.