Suspensions of cellulose microfibrils resulting from the homogenization of parenchymal cell walls were surface silylated with isopropyl dimethylchlorosilane. When mild silylation conditions were applied, the microfibrils retained their morphology, but could be dispersed in a non-flocculating, manner into organic solvents. The rheological properties of these suspensions in methyl oleate were investigated, using a range of concentrations and shear rates. The suspensions presented characteristic thickening and shear thinning effect, but no marked yield stress point. These properties are discussed and compared with those of the aqueous suspension of the parent un-derivatized microfibrils. (C) 2003 Elsevier Ltd. All rights reserved.