In this paper, structural and electrical studies of A-site lanthanum-substituted Sr1-xLaxBi 2Nb2O9; x=0.0-0.5 ceramics are reported. The introduction of lanthanum produces pore-free microstructure upto x=0.3. A diffuse ferroelectric to paraelectric phase transition is observed in the doped samples and positive temperature coefficient of resistance (PTCR) is observed in x=0.0, 0.4 and 0.5 samples whereas x=0.1-0.3 samples show negative temperature coefficient of resistance (NTCR). Curie temperature decreases continuously with increase in lanthanum content. © 2005 Elsevier B.V. All rights reserved.