Fever is a natural protective response of the host organism. Mild to moderate fevers, up to 40.0°C, have immunological benefits and do not need to be reduced. However, parents regularly reduce fever with medications to prevent perceived harmful outcomes. This study identified the determinants of parents’ intentions to reduce childhood fever with medications. A community-based cross-sectional survey was conducted with 391 Australian parents of children aged between 6 months and 5 years. Recruitment was through advertising, face-to-face and snowball methods. The survey targeted constructs of the Theory of Planned Behavior: attitudes, subjective norms, perceived behavioral control, intentions and previously identified background factors. Structural equation modeling identified 69% of the variance in intentions. The strongest influences were from non-scientifically based attitudes (phobic) (β=0.55) and subjective norms (husband/partner and doctors) (β=0.36). Attitudes (β=0.69) and subjective norms (β=0.52) were strongly determined by child medication behavior (whether the child took medications easily when febrile) which had a total effect on intentions of β=0.66. Perceived control, education and number of children had minimal influence on intentions. There is an urgent need for (i) the education of both parents in the benefits of fever and (ii) for doctors to consistently provide parents with evidence-based information.