Purpose of review: Review of recent developments in the field of cross-reactivity in food allergy and the clinical relevance of these developments. Recent findings: New foods have been added to the list of Bet v 1 and profilin-related food allergies. Clinical relevance of cross-reactions based on recognition of carbohydrate determinants and profilin is limited for the population of pollen-allergic patients as a whole. For selected food allergic patients, however, N-glycans and particularly profilin are potentially of clinical relevance. Lipid transfer proteins have further been established as clinically more severe allergens in several foods. This severity is attributed to their stability to proteolysis and processing. Storage proteins of several nuts and seeds have been identified as important allergens, but cross-reactivity between storage proteins of different foods appears to be limited. Using cross-reactivity as the basis for immunotherapy in food allergy seems promising but needs confirmation by double-blind, placebo-controlled trials. Summary: The continued identification and characterization of cross-reactive allergens facilitates the study of factors determining clinical relevance of cross-reactivity and of possible efficacy of immunotherapy in food allergy.