BiFeO3 nanoparticles were prepared by a wet chemical synthesis method. Transparent films were deposited on glass and quartz substrates by dip and spin coating processes from the synthesized sol. We obtained thicker films (similar to 2 mu m) by dip coating process and thinner films (similar to 200 nm) by spin coating process. Transmission electron microscopy images confirmed that the particles are nanocrystalline in size. From the optical transmittance spectra the band gap of the BiFeO3 nanoparticles was determined in the range of similar to 3.03-2.88 eV (similar to 410-430 nm). Electrical resistivity, polarization, zero-field-cooled and field-cooled magnetizations versus temperature characteristics were also studied for these films. (C) 2009 Elsevier B.V. All rights reserved.