In this work, Polypyrrole (PPy), Titanium dioxide nanofiber (TiO2-nf) are prepared by oxidative polymerization and hydrothermal process respectively. The PPy/TiO2-nf composite is prepared by in situ oxidative polymerization in the presence of pyrrole monomer and TiO2-nf. The nanocomposite and TiO2-nf are then characterized by scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX) techniques and XRD studies. Dielectric studies of PPy/TiO2-nf composite is carried out in the frequency range of 1 KHz-3 MHz at varying temperature and it shows anomalous behavior at 1MHz, where its value reaches to its minimum value of 13 at room temperature and this dip remains even at higher temperature. Impedance study is used to understand the grain and grain boundary effects of the material; frequency dependent ac conductivity has two regions separated at 1MHz, which is being explained by hopping conduction and Maxwell-Wagner type mechanism, respectively. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2014, 131, 40036.