Introduction: Food allergy is a recognized health problem, but little has been reported on its cost for health services. The EuroPrevall project was a European study investigating the patterns, prevalence and socio-economic cost of food allergy. Aims: To investigate the health service cost for food-allergic Europeans and the relationship between severity and cost of illness. Methods: Participants recruited through EuroPrevall studies in a case-control study in four countries, and cases only in five countries, completed a validated economics questionnaire. Individuals with possible food allergy were identified by clinical history, and those with food-specific immuno-globulin E were defined as having probable allergy. Data on resource use were used to estimate total health care costs of illness. Mean costs were compared in the case-control cohorts. Regression analysis was conducted on cases from all 9 countries to assess impact of country, severity and age group. Results: Food-allergic individuals had higher health care costs than controls. The mean annual cost of health care was international dollars (I$)2016 for food-allergic adults and I$1089 for controls, a difference of I$927 (95% confidence interval I$324-I$1530). A similar result was found for adults in each country, and for children, and was not sensitive to baseline demographic differences. Cost was significantly related to severity of illness in cases in nine countries. Conclusions: Food allergy is associated with higher health care costs. Severity of allergic symptoms is a key explanatory factor.