Polarographic behavior of cephalosporin cefetamet-Na (Cef-Na) in aqueous solutions of pH ranging from 1.7 to 12.5 was investigated by applying direct current (dc) polarography, differential pulse polarography (dpp), alternating current (ac) polarography, cyclic voltammetry and electrolysis at constant potential. The characteristics of the corresponding electrode reaction are presented and discussed. The electrode reaction was found to be affected by strong adsorption, strongly and slightly pronounced in acidic and alkaline media, respectively. The methoxyimino group electroreduction was carried out and the mechanistic scheme was suggested. In addition, a sensitive dpp method was proposed for analytical determination of a very low concentrations of Cef-Na.