The electrochemical study of β-chlorovinylaldehydes, namely, 4-chloro-3-formyl-2H (1)-benzopyran and β-chlorocinnamaldehyde was carried out in DMF in the presence of 0·1 M NBu4ClO4 as the supporting electrolyte. Both the depolarizers give three diffusionlimited polarographic waves and the corresponding cathodic peaks in cyclic voltammetry. Their microcoulometric data indicate a transfer of four-electrons (napp=4) in the electrode process. The macroscale controlled-potential electrolysis of the depolarizers afforded only blackish-brown tarry product. A mechanism is suggested for their reduction in DMF under polarographic conditions. © 1981 Indian Academy of Sciences.