Preparation, dielectric, piezoelectric, hysteresis, impedance spectroscopy and AC conductivity studies in the Pb0.8K0.4Nb2O6 ferroelectric ceramic have been presented. The Pb1-xK2xNb2O6 (PKN) characterized for ferroelectric and impedance spectroscopy studies from room temperature to 600 degrees C. The sample shows a single phase with orthorhombic structure from X-ray diffraction studies. The Cole-Cole plots and electric modulus plots at different temperatures are drawn. The results obtained from the impedance spectroscopy are analyzed, to understand the conductivity behavior of PKN. The piezoelectric constant, d(33), has been found to be 75 x 10(-12) C/N. (c) 2006 Elsevier B.V. All rights reserved.