Yttrium hydroxide nanotubes were hydrothermally synthesized via a metastable precursor, PEG-Y(NO3)(3) complex. XRD patterns showed the product was a pure hexagonal phase of Y(OH)(3). TEM images displayed that the nanotubes have outer diameters ranging from 80 to 200 nm, wall thicknesses of about 30 nm, and lengths up to several micrometers. The nanotube growth may have three stages: formation of a metastable PEG-Y(NO3)(3) complex; nucleation and formation of Y(OH)(3) nanorods; developing Y(OH)(3) nanotubes. We proposed the Y(OH)(3) nanotubes growth mechanism to be a nucleation-diffusion growth based on the characterization results. Y2O3 nanotubes were formed with smaller diameters after post-treatment at 500degreesC for 2 h. (C) 2003 Elsevier B.V. All rights reserved.