Co-W thin films were electrodeposited from aqueous bath with different organic additives. Electrochemical analysis showed that the transient state was limited and polarization behaviors were more evident during Co-W electrodeposition in the presence of organic additives. SEM measurement indicated that the surface morphology was affected by the nature of the organic additives to a large extent. Homogeneous Co-W thin films were obtained from the solutions containing ethyl methacrylate. Moreover, it was obvious that the presence of organic additives, in the electroplating bath, modified the structure and magnetic properties of the Co-W thin films according to the XRD and VSM measurements. (c) 2007 Elsevier B.V All rights reserved.