The electrochemical behavior of 1,2-dihydropyridazine-3,6-dione (3,6-dihydroxypyridazine) on glassy carbon electrode in aqueous and some organic solvents was investigated. The results indicate that the electrochemically generated pyridazine-3,6-dione is unstable and via oxidative ring cleavage converts to maleic acid. Also, the results show that the rate of oxidative ring cleavage depends on electrolysis media. In addition, the observed homogeneous rate constant of oxidative ring cleavage of 1,2-dihydropyridazine-3,6-dione was estimated by comparing the experimental cyclic voltammetric responses with the digital simulated results in aprotic solvents. Furthermore, some kinetic parameters related to irreversible cathodic electron transfer process of 1,2-dihydropyridazine-3,6-dione was estimated in aqueous solutions. (C) 2011 Elsevier Ltd. All rights reserved.