The electrical properties of banana fiber-reinforced phenol formaldehyde composites have been studied with special reference to fiber loading, fiber treatments, and hybridization with glass fibers. The dielectric constant decreased with frequency and fiber loading. Treatments with silanes, NaOH and acetylation, latex treatment, heat treatment, and cyanoethylation decreased the dielectric constant value. The dielectric constant is higher for banana/PF composites than that of glass/PF composites. In hybrid composites, the dielectric constant decreased with increase in glass fiber concentration. The volume resistivity of banana fiber-reinforced phenol formaldehyde composites decreased with frequency and fiber loading. Chemical modifications in the fiber increased the volume resistivity of the composites. Volume resistivity of banana/glass hybrid composites increased with increase in glass fiber content. Layered composites with glass fiber at periphery were found to have higher volume resistivity than other layering patterns. The loss factor decreased by the chemical treatments and in hybrid composites it decreased with increase in volume fraction of glass fibers. (C) 2008 Wiley Periodicals, Inc.