A facile solution-phase approach has been developed to selectively fabricate metastable molybdenum dioxide, MoO2, nanocrystallites in an ethylene glycol/water mixed solvent. The experimental results reveal that the volume ratio of ethylene glycol has an important influence on the phase of the products based on XRD characterization. To our knowledge, it is the first time that metastable MoO2 nanocrystallites were synthesized through a solution route under mild conditions. (c) 2005 Elsevier B.V. All rights reserved.