Summary Background Food allergy is common, especially in childhood, where 6–8% of children are affected. Identification of early and efficient markers for later development of food allergy is very important. Objective We examined the ability of repeated measurements of food sensitization in early childhood to predict doctor‐diagnosed food allergy (DDFA) at the age of 6 years. Methods The analysis was based on data from a prospective birth cohort study. Information was collected by parental questionnaires, and blood samples were obtained at 2 and 6 years of age. Children with repeated determination of sensitization to food allergens at 2 and 6 years of age were categorized into the sensitization phenotypes: no, early onset, late onset and persistent sensitization. The association between sensitization phenotypes and DDFA was prospectively investigated using multiple logistic regression analyses. Results Of 3097 children recruited at birth, a complete follow‐up of IgE measurements and questionnaires at 1.5, 2 and 6 years were available for 1082 children. Early food allergen sensitization (fx5) was a strong risk for DDFA at 6 years odds ratio (OR)=4.7; 95% confidence intervals (95% CI) 2.0–11.2 and for a new onset of DDFA at 6 years (OR=4.1; 95% CI 1.5–11.3). Additionally, persistent food allergen sensitization increased the risk of DDFA at 6 years (OR=6.1; 95% CI 2.7–13.7). Early sensitized children with a history of parental atopy showed the highest risk for DDFA at 6 years. Conclusion Food‐sensitized children during the first 2 years of life, especially with a family history of atopy, might be considered as a susceptible subgroup that requires specific attention concerning the development of food allergy‐related symptoms. >Cite this as: E. Schnabel, S. Sausenthaler, B. Schaaf, T. Schäfer, I. Lehmann, H. Behrendt, O. Herbarth, M. Borte, U. Krämer, A. von Berg, H.‐E. Wichmann, J. Heinrich, and for the LISA Study Group, Clinical & Experimental Allergy, 2010 (40) 450–457.