The in situ variation of induced orientation within a liquid crystalline polyester under the influence of a magnetic field was investigated during heat treatment, by means of wide-angle X-ray scattering (WAXS) using synchrotron radiation. The kinetics of molecular orientation, both from the melt and from the solid state, is analyzed in a wide temperature range (T = 190-260degreesC) in terms of the variation of the Hermann's orientation function, as derived from the analysis of the WAXS patterns. The temperature range examined corresponds to the coexistence of. both, the nematic and the isotropic phases. The orientation function data are discussed in the light of Kohlrausch-Williams-Watts equation. Results reveal that the final degree of orientation reached shows a maximum around 200-230degreesC that depends on whether the molecular orientation is developed during cooling down from the molten state or whether it arises upon heating up from the solid state. In the latter case, the orientation rate is found to be higher owing to the initial director orientation field at right angles from the magnetic field. (C) 2003 Elsevier Ltd. All rights reserved.