Samples of Bi4CexV2-xO11-(x/2)-delta were prepared by the conventional solid-state reactions. The phase transition changes were studied by combining results obtained from high temperature X-ray powder diffraction (HT-XRPD), differential thermal analysis (DTA) and conductivity measurements. For x = 0.15 composition, the phase transitions; alpha <-> beta and beta <-> gamma were clearly evident in the temperature ranges 423-450 and 533-550 degrees C, respectively. Although no subtle change in variation of the unit cell parameters was observed for x = 0.25 composition, the Arrhenius plot and DTA thermogram showed evidence of gamma' <-> gamma phase transition in the temperature range 450-500 degrees C. (C) 2009 Elsevier B.V. All rights reserved.