This paper reports a study of electrodeposition of SmCo in aqueous solution using a Hull cell. Different concentrations of cobalt ion in the electrolyte, addition of supporting electrolyte and different deposition time have been tested. High samarium contents and thicknesses have been obtained: up to 50% of Sm in the deposit and several microns. The oxygen contamination is linked to the samarium content and two elaboration parameters have been found for limiting this contamination: addition of supporting electrolyte and long deposition time. (C) 2012 The Electrochemical Society. [DOI: 10.1149/2.051210jes] All rights reserved.