In this paper a Metamaterials Reconfigurable Multiband Antenna is designed. The design consists of a rectangular patch antenna surrounded by an arrangement of cross shaped metamaterials cells that have two different behaviours and can be controlled electronically in order to switch between the two different behaviours; therefore, the antenna will have a controllable size according to the surrounding area behaviour. The obtained results show that the antenna operates at different frequencies. We demonstrate the possibility to design a metamaterials based frequency agile antenna.