Laser ablation of an iron target in water and acetone has been carried out using a frequency doubled Nd:glass laser source (pulse duration of 250 fs and frequency repetition rate of 10 Hz). The observation of the nanostructures formed in the laser irradiated region of the metallic target and fast shadowgraphic analysis of the laser induced cavitation bubble have been performed in order to correlate the size distribution of the obtained nanoparticles to the dynamics of the ablation process. The composition, morphology and oxidation state of the synthesized nanoproducts have been investigated by XPS (X-ray Photoelectron Spectroscopy), TEM (Transmission Electron Microscopy) and microRaman spectroscopy. The experimental data support a relationship between the nanoparticles size distribution and the femtosecond laser ablation mechanism, while the chemical and structural characteristics of the nanoparticles can be tuned by varying the liquid medium. (C) 2015 Elsevier B.V. All rights reserved.