The aim of this work is to develop a controllable synthesis pathway which produces a stable alumina layer on the surface of carbon nanotubes by impregnation method. Precursor compounds such as aluminium isopropoxide and aluminium-acetylacetonate were used to cover the surface of multiwalled carbon nanotubes (MWNTs) under different solvent conditions. As prepared alumina coverages were characterized by TEM, SEM, SEM-EDX, TG and X-ray diffraction techniques. Results revealed that homogeneous coverage can be achieved in a controllable way. (C) 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim