Bamboo fiber-reinforced epoxy composites were fabricated with untreated and alkali treated bamboo fibers. Dielectric, electric modulus, ac, and dc conductivity studies were carried out to rationalize the dielectric behavior of bamboo/epoxy composites. Composites of two fiber orientation parallel and perpendicular to the electric field were prepared. The dielectric behavior and electric modulus spectra of the composites were characterized using standard impedance analyzer. Dielectric properties were analyzed as a function of frequency (95 Hz-2 MHz) for temperatures in the range from 30 to 180 A degrees C. Real part of dielectric constant (epsilon'), conductivity, and dielectric dissipation factor (tan delta) of 0A degrees oriented bamboo/epoxy composites were higher than that of 90A degrees oriented composites. Conductivity activation energy, tan delta, epsilon', and volume resistivity decreased with increase in frequency at all the temperatures under study. Mercerization reduces the water absorption in bamboo fibers and thus improves corresponding dielectric properties of composites. Relaxation times 39.80 mu s and 258.5 mu s for 0A degrees and 90A degrees oriented bamboo/epoxy composites were calculated respectively from the relaxation peaks observed in electric modulus spectra at 180 A degrees C.