Department of Chemistry, Sri Venkateswara University, Tirupati-517 502 Manuscript received 21 December 1992, revised 10 June 1993, accepted 15 June 1993 The electrochemical reduction behaviour of aldicarb [2-methyl-2-(methylthio)propanaldehyde-O-(methylcarbamoyl)oxime] (1), an insecticide has been studied in the pH range 2-12 including 1 M HCI04 and 1 M HCl in EtOH-water mixtures by employing d.c. polarography, cyclic voltammetry, a.c. polarography and differential pulse polarography. The number of electrons in the electrode process is determined by millicoulometry. The azomethine group is found to be reducible in 4e- process in solutions of pH \(\leq\) 4. The C=N-O linkage is observed to be reduced by a mechanism involving reductive fission of the N-O bond. Kinetic parameters such as diffusion coefficient and heterogeneous forward rate constants have been evaluated and reported.