We report on the generation of Ni nanoparticles and the synthesis of magnetic nanoparticles films by 100 femtosecond (fs) Ti:sapphire laser ablation in vacuum. The nanoparticles sizes have been studied by atomic force microscopy, showing a mean size of approximate to 40 nm. Vibrating sample magnetometry analysis has been performed to characterize magnetic properties of the deposited nanoparticles layers. The hysteresys loops clearly indicate that the Ni nanoparticles film behaves as a system of isolated magnetic particles. Our results evidence the potentiality of fs laser ablation, in vacuum, for the generation of nanoparticles and the deposition of nanoparticles films of magnetic materials. (c) 2005 Elsevier B.V. All rights reserved.