Pistachio and cashew contain allergenic proteins, which causes them to be removed from the diet of allergic people. Former evidences have demonstrated that food processing (thermal and non-thermal) can produce structural and/or conformational changes in proteins by altering their allergenic capacity. In this study, the influence of Instant Controlled Pressure Drop (DIC) on the pistachio and cashew allergenic capacity has been studied. Western blot was carried out using IgG anti-11S and anti-2S and IgE antibodies from sera of patients sensitized to pistachio and cashew. DIC processing causes changes in the electrophoretic pattern, reducing the number and intensity of protein bands, as the pressure and temperature treatment increment what results in a remarkable decrease of detection of potentially allergenic proteins. The harshest conditions of DIC (7bar, 120s) markedly reduce the immunodetection of allergenic proteins, not only by using IgG (anti 11S and anti 2S) but also when IgE sera from sensitized patients were used for Western blots. Such immunodetection is more affected in pistachio than in cashew nuts, but it not completely removed. Therefore, cashew proteins are possibly more resistant than pistachio proteins. According these findings, Instant Controlled Pressure Drop (DIC) can be considered a suitable technique in order to obtain hypoallergenic tree nuts flour to be used in food industry.