This study reports the synthesis of bismuth ferrite (BFO) by a facile wet chemical hydro-evaporation (HE) method and the effect of different annealing temperatures (450 degrees C, 550 degrees C and 650 degrees C) on the phase evolution, morphology, physical properties of the synthesized BFO. It is observed that the BFO phase is formed at all the three annealing temperature and the morphology is found to be flowers and spherical. Magnetization studies revealed that the BFO formed at 450 degrees C and 650 degrees C exhibits its typical anti-ferromagnetic nature while the BFO formed at 550 degrees C exhibits weak ferromagnetic nature. The observed weak ferromagnetism in BFO owes to the point defects associated with oxygen vacancy defects as well as the smaller size effect. The possible origin of the enhancement in magnetic property has been explained with a suitable model in terms of particle size and defects in the material. (C) 2013 Elsevier Ltd. All rights reserved.