The electroreduction of 2,2’-dinitrobiphenyl in anionic, cationic, and nonionic micellar solutions is investigated by polarography and cyclic voltammetry. The mechanism of the reduction is compared to the reduction mechanism of the same compound in a homogeneous water solution. The reduction takes place in two irreversible electron transfer steps. The half-wave potentials and the currents for both reduction steps depend on the type of micelles. The surfactants compete for adsorption sites on mercury, resulting in a shift of the reduction potential. The apparent diffusion coefficients of 2,2’-dinitrobiphenyl in micellar systems are also reported.