We report a successful fabrication of 300 nm thick carbon nanotubes and Pb(Zr0.52Ti0.48)O-3 (CNT-PZT) nanocomposite thin films with annealing temperature as low as 500 degrees C in H-2/N-2 atmosphere. Realizing the thickness of CNT-PZT nanocomposite thin films down to few hundred nanometers is one way to reduce the operating voltage of its application to micro- or nano-electromechanical system. The field emission scanning electron microscopic and atomic microscopic analysis revealed that the nanocomposite thin films annealed in H-2/N-2 atmosphere exhibits the most favorable surface morphology with adequate perovskite (111) reflection of PZT based on Xray diffraction analysis. The measured dielectric constant and loss tangent of the nanocomposite thin films show that the annealing duration of 30 min promotes the optimum dielectric properties of the nanocomposite thin films. Our observations suggest that the annealing atmosphere and duration are important parameters in controlling the crystallization behavior hence the dielectric properties of the nanocomposite thin films, which can be readily applicable to other nanocomposite thin films. (C) 2014 Elsevier B.V. All rights reserved.