A series of cobalt (Co) nanoparticles were synthesized by employing PAMAM dendrimers with different generations (G 0.0-3.0) as templates and sodium borohydride as a reducing agent. Extensive characterizations of the products were done using TEM, FT-IR, VSM, TGA, and XPS. The magnetization curves have superparamagnetic non hysteric characteristic at lower fields and with nonsaturation characteristic at high fields. All XRD patterns indicate that amorphous structure of all products. The shake-up satellites are observed at higher energies of the XPS peaks. (C) 2011 Elsevier B. V. All rights reserved.