The development and electrical characterization of Sisal powder filled Polyvinyl alcohol (PVA) composites is reported. Effect of temperature and frequency variation on dielectric constant (ε’), dielectric dissipation factor (tan δ) and on a. c. conductivity (σa.c.) were determined. With the increase of filler content, the dielectric constant increased, it was mainly due to motion of the dipolar groups of the interfacial polarization occurring in the composites. The conductivity increased with rise in temperature. Differential scanning calorimetry (DSC) scans were run by using a Mettler DSC. Tm of PVA was little affected on adding untreated sisal fibre powder .On adding treated sisal fibre a new degradation peak appeared around 290 oC.