Chemistry Department, Faculty of Science, Mansoura University, Mansoura, Egypt Manuscript received 2 August 1992, revised I 1 October 1993, accepted 16 November 1993 Polarographic reduction of benzyl disulphide shows two waves corresponding to the reduction of S-S and CH2SH bonds, while the reduction of p-tolyl disulphide occurs over one two-electron wave. Effect of pH, nature of waves and reduction mechanism have been discussed. In this connection kinetic studies for the decomposition of S-S bond in p-tolyl disulphide have been carried out at different pH values.