Background: Profilin is a small actin-binding protein that contributes to the allergenic potency of many fruits and vegetables, including tomato. Two highly similar genes encoding tomato profilin have been isolated and designated as allergen Lyc a 1.01 and Lye a 1.02. Objective: The aim of the study was to generate profilin-reduced hypoallergenic tomato fruits by silencing of both genes in transgenic tomato plants by means of RNA interference (RNAi). Methods: The efficiency of gene silencing was documented by means of Northern blotting, immunoblotting, and skin prick testing. Results: Quantification of the remaining protein revealed that profilin accumulation in transgenic fruits was decreased 10-fold compared with that seen in untransformed controls. This decrease was sufficient to cause a reduced allergenic reactivity in patients with tomato allergy, as determined with skin prick tests. Because most patients with tomato allergy are not monosensitized to profilin, the IgE reactivity to the profilin-silenced tomato fruits in vivo varied widely between individuals tested. Conclusion: We could demonstrate the efficient silencing of both profilin genes in transgenic tomato plants using RNAi This resulted in Lyc a 1-diminished tomato fruits, providing proof of concept and demonstrating that RNAi can be used to design allergen-reduced food. However, simultaneous silencing of multiple allergens will be required to design hypoallergenic tomatoes. Clinical implications: Our findings demonstrate the feasibility of creating low-allergenic food by using RNAL This concept constitutes a novel approach to allergen avoidance.