Raman scattering measurements were carried out for Fe3O2BO3 and Ni2FeO2BO3 ludwigite crystals in the temperature range from 15 to 300 K. At room temperature ludwigite has an orthorhombic structure belonging to space group D-2h(9). Attempts made to record polarized Raman spectra were successful, and we were able to identify most of the phonons belonging to A(1g) species. A careful analysis of the spectra shows that the observed Raman modes do not exhibit variations either in wavenumber or intensity or both with temperature, indicating that the D-2h(9) phase does not undergo any structural modification in the temperature range investigated. Also, we observed for Fe3O2BO3 ludwigite the appearance of a continuous scattering background in the phonon spectrum for temperatures below 200 K. This background, which is due to electronic transitions between Fe2+ and Fell ions, is related to the charge delocalization effect. Copyright (C) 2002 John Wiley Sons, Ltd.