This chapter explains the piezoelectric materials in use for vibrational energy harvesters, and explains the physics underpinning vibrational energy harvesting, namely piezoelectricity, in order to identify the properties required for a good material. It describes the perovskite family, in which lead zirconate titanate (PZT) lies, and explains fabrication processes and main characteristics of ceramics, screenprinted layers, single crystals, and thin films. The chapter focuses on perovskite lead‐free materials, and describes Wurtzite thin films such as aluminum nitride (AlN) and zinc oxide (ZnO). The chapter discusses the polymers such as polyvinylidene fluoride (PVDF), which stand for a very exciting area of research for energy harvesting. It describes the latest developments performed with nanomaterials, especially ZnO nanowires (NWs). The future of these harvesters is therefore fully linked to cheap and large area technology, contrary to what has been thought initially with microsystems.