Monodispersed Mn3O4 nanoparticles with diameter of about 10 nm were synthesized via a simple low-temperature esterification process. It was found that the particle size could be tailored by varying the synthesis temperature. The materials showed catalytic activity in the oxidation of hydrocarbons with molecular oxygen under solvent- and additives-free conditions. (C) 2008 Elsevier B.V. All rights reserved.