The demand for flexible and wearable wireless systems is increasing exponentially in today’s information-oriented society. Flexible electronic systems are equally beneficial and have wide applications in communication, medicine, military and radio frequency applications. Beginning with a detailed review of flexible materials which have been used during the last few decades, an overview of some abundantly used polymer substrates is provided, which compares their physical, electrical and mechanical properties. The polymers are highly resistant nonconductive materials made up of repeated subunits of hydrocarbons known as monomers. Polymers are widely used for different antennas and Radio Frequency Identifications (RFID) to facilitate bending and flexibility as a substrate such as polyimides (PI), polydimethylsiloxane (PDMS), polytetrafluoroethylene (PTFE), Rogers RT/ Duroid and Liquid Crystal Polymer (LCP). Flexible substrates have become essential to provide increased flexibility in we