Department of Chemistry, Sri Krishnadevaraya University, Anantapur-515 003, India Manuscript received 28 January 1998, revised 2 June 1998, accepted 8 June 1998 The polarographic behaviour of 3-methyl-4-(4'-substituted-benzeneazo)-2-isoxazolin-5-ones has been studied in 50% (v/v) dimethylformamide solution in Britton-Robinson buffer of pH 4.1 at different temperatures (303.15-333.15 K). The reduction is found to be diffusion-controlled and irreversible at different temperatures. The shift of E1/2 values towards more negative potentials and decrease in the values of α\(n\)a and \(k_f^o\),h suggest that the electrode reaction becomes more irreversible at elevated temperatures. The thermodynamic quantities have been evaluated.