Silica-supported nickel catalysts have been prepared by a solventless technique involving the deposition of the [Ni(tmen)(acac)(2)] precursor from the gas phase. According to UV - vis and IR spectroscopy and to elemental analysis, the initial deposition step results in the grafting of Ni(II) complexes on silanol groups to give predominantly [Ni(acac)(2) ( = Si- OH)(2)](0) monomeric inner-sphere complexes, with elimination of the neutral ( tmen) ligands into the gas phase. Subsequent thermal treatments in oxidising atmospheres causes an oxidative decomposition of the ( acac) ligands without nickel desorption or coalescence into oxide crystallites. The ensuing coordinatively unsaturated Ni( II) centres are reduced to Ni(0) by flowing hydrogen at low temperatures ( 300 degrees C), yielding nanosized Ni particles as evidenced by TEM and O-2 titration. Thus, the gas-phase deposition technique represents an interesting alternative to conventional "wet'' deposition procedures since it allows one to obtain well-dispersed supported nickel catalysts by reduction at low-temperatures.