AbstractHigh permittivity materials find extensive use in high frequency communications devices due to their small size (compared to lumped element circuits), low losses and physical robustness. Recently, these types of materials have been applied in high field magnetic resonance imaging, based upon earlier work in electron paramagnetic resonance. This review article describes the basic properties of high permittivity materials, how they can be formed into both discrete resonators and also into deformable water‐based suspensions, and how these different structures can be used to improve many aspects of high frequency magnetic resonance. © 2011 Wiley Periodicals, Inc. Concepts Magn Reson Part A 38: 148–184, 2011.