The kinetic parameters and pathways of decay of the cation-radicals formed as primary products in the course of electro-oxidation of the eaters of 1,2- and l,4-dihydropyridine have been studied by rotating ring-disk electrode (rrde) method in temperature range from +20 degrees C to -30 degrees C. Two ways of the decay of these cation-radicals, ie via loss of H+ and via loss of H-. operating simultaneously have been proved to be possible. Competition between these two ways depends on the influence of temperature and on electronic effects of the substitutes attached to the dihydropyridine ring. Cation-radicals of 1,2-dihydropyridine derivatives the sufficiently more stable than those of 1,4-dihydropyridines due to a more extended common pi-electron system of the latter. 1,2-Dihydropyridine derivatives are oxidized more readly (by 200-250 mV) than the corresponding 1,4-dihydropyridines.