Nanodielectrics is an emerging area of research because of its potential application in energy storage and transducers. One-dimensional metallic nanostructures with localized electronic wave functions show giant dielectric constant. Following the prediction, during the last couple of years we have investigated the effect of giant permittivity in one-dimensional systems of conventional metals and conjugated polymer chains. In this article, we have tried to summarize the works on giant permittivity and finally the fabrication of nanocapacitor using metal nanowires, which shows giant permittivity is also discussed.