This contribution describes the development of an impedimetric immunosensor for atrazine detection. This immunosensor is based on the use of interdigitated metallic p-electrodes (IDμEs). The method described in this work does not use any redox mediator and relies on the direct detection of the immunochemical competitive reaction between the pesticide and a haptenized-protein immobilized on interdigitated p-electrodes for the specific antibody. The immunoreagents used were specifically developed to detect atrazine. The immunochemical detection of this pesticide is achieved without using any label. The immunosensor shows a limit of detection of 8.34±1.37 pg L-1, which is lower than the Maximum Residue Level (MRL) (50 μg L-1) established by EU (European Union) for residues of atrazine as herbicide in the wine grapes and other foodstuff products.