Objective: The high incidence of foodborne disease among children suggests the value of health promotion. Children are a high-risk group so far as foodborne disease is concerned, although they may be hard to reach with training programmes. This research investigated the use of drawings, compared with questionnaires, to evaluate the impact of a health promotion programme to improve knowledge and habits in the context of food handling and personal hygiene. Setting: Children (184) attending primary school and living in the north of Italy were enrolled in the programme. Methods: Qualitative and quantitative tools: pre- and post-intervention questionnaires were administered, and children were asked to produce pre- and post-intervention drawings about microorganisms and their effects on humans. An observation grid was built to code key features in the drawings. Results: Results clearly showed that some drawing features correlated with and predicted high scores in the questionnaire on knowledge of microorganisms. These were the use of captions, the representation of a natural context and the presence of a causal link between depicted elements. Conclusion: Study findings highlight the potential of the use of drawing as an effective evaluation tool. The use of drawing can support the design of strategies for the validation of health campaigns aimed at the amelioration of children's food contamination-related (and perhaps other) risks.