A low-temperature hydrothermal reaction is provided to generate crystalline perovskite nanotubes such as barium titanate (BaTiO.sub.3) and strontium titanate (SrTiO.sub.3) that have an outer diameter from about 1 nm to about 500 nm and a length from about 10 nm to about 10 micron. The low-temperature hydrothermal reaction includes the use of a metal oxide nanotube structural template, i.e., precursor. These titanate nanotubes have been characterized by means of X-ray diffraction and transmission electron microscopy, coupled with energy dispersive X-ray analysis and selected area electron diffraction (SAED).