One of the major challenges of printed electronics is to develop materials for flexible devices. Among these latter, antennas occupy a place of choice because of the new applications which are emerging. In this paper a flexible antenna based on a new nanocomposite, Polyaniline (PANI) charged by nanopowder of Iron-Nickel (Fe-Ni), operating in dual-band ([2.4-2.48] and [5.15-5.825] GHz) is proposed. This antenna, triangular/circular shaped with a coplanar waveguide (CPW) feeder to achieve wideband performance is printed on a 130μm thick Kapton® substrate. The nanocomposite fabricated (PANI/Fe-Ni), whose morphology was studied via scanning electron microscopy, has a conductivity of 9600 S/m. The performance of the antenna is analyzed through simulations and measurements which demonstrate a good agreement between each other. A maximum gain of 2.8 dBi for a 90μm thick nanocomposite is obtained. © 2019 European Association on Antennas and Propagation.