Health education is to foster health literacy, informed decision-making and to promote health behaviour. To date, there are several models that seek to explain health behaviour (e.g. the Theory of Planned Behaviour or the Health Belief Model). These models include motivational factors (expectancies and values) that play a role in decision-making in health contexts. In this theoretical paper, it is argued that none of these models makes consequent use of expectancy-value pairs. It is further argued that in order to make these models fruitful for science education and for informed decision-making, models should systematically incorporate knowledge as part of the decision-making process. To fill this gap, this theoretical paper introduces The Integrated Model of Decision-Making in Health Contexts. This model includes three types of knowledge (system health knowledge, action-related health knowledge and effectiveness health knowledge) as influencing factors for motivational factors (perceived health threat, attitude towards health action, attitude towards health outcome and subjective norm) that are formed of expectancy-value pairs and lead to decisions. The model's potential for health education in science education as well as research implications is discussed.