Small and wide-angle X-ray scattering experiments with in-situ deformation of dry flax fibres have been carried out. An increase in the (200) peak intensity during deformation has been attributed to strain-induced crystallisation of the cellulose microfibrils, and provides evidence that the non-crystalline cellulose chains are initially oriented. However, no change in the equatorial small-angle streak (from cellulose microfibrils), the meridional reflection (from a crystalline/non-crystalline repeat along the fibre), or the microfibril orientation was seen. (C) 2003 Kluwer Academic Publishers.