Silica nanotubes with controlled diameter and length were synthesised by using a novel and modified template-sol-gel method. The consistency and order of silica nanotubes mainly depend on the anodic alumina membrane (AAO) template that was used during the preparation process. The AAO membrane was chemical etched using different concentrations (5, 7 and 10 wt %) of phosphoric acid. The obtained silica nanotubes had diameters in the range of 220-280 nm and thicknesses around 70-90 nm as observed by field emission scanning electron microscopy (FESEM). Scanning transmission electron microscopy (STEM) images enable us to view the arrangement of the hollow cylindrical silica nanotubes. Porosity of the silica nanotubes was investigated by nitrogen adsorption-desorption. The mesoporous silica nanotubes show characteristic type IV isotherm behaviour, with double capillary condensation step in the relative pressure range of 0.2-1.0 (p/p0). Thermogravimetric (TGA) and differential thermal (DTA) analyses confirm the thermal stability of the silica nanotubes and their weight changes and endo and exothermic reactions. The structural and functional group analyses of the silica nanotubes were carried out by using X-ray diffraction (XRD) patterns and Fourier transform infrared spectroscopy (FT-IR). � (2016) Trans Tech Publications, Switzerland.