Nanoparticles with optical and magnetic responses are of great applicability in different fields. In this work, zero valent iron nanoparticles were prepared by laser ablation and stabilized in a surfactant solution to keep particles dispersed and protected in the solution. Optical and magnetic properties of nanoparticles were measured, by UV and Mossbauer spectroscopy. The results show the formation of nanoparticles of alpha-Fe (ferromagnetic). Our method of preparation, which uses a high H+ concentration in the medium, diminishes the zero valent iron oxidation, producing iron nanoparticle with a core of alpha-Fe and a small shell probably composed of iron oxides. (C) 2011 Elsevier B. V. All rights reserved.