Electrical behaviour of compositions with x <= 0.100 in the BaSn1-xNbxO3 system has been studied by employing complex impedance method in the temperature range 300-500 K and in the frequency range 100 Hz-10 MHz. An equivalent electrical circuit model, which contains a series arrangement of two parallel RC elements, is proposed to represent the electrical characteristics of the material. These studies show the contributions of two processes to the electrical conductivity, which are attributed to the activated hopping processes within the bulk. Electrical conduction behaviour has been explained in terms of the defect structure model. (c) 2005 Elsevier B.V. All rights reserved.