The kinetics of the hydrolysis of hydrazpne derived from nitropyridine 2-carboxaldehyde and 2-hydrazino-4-substituted thiazoles la-e in 10% (v/v) DMF-buffer mixture has been investigated by applying two independent and different techniques viz UV-spectrophotometry and differential pulse, polarography (DPP). The hydrolysis has been found to follow general acid-base catalysis. Mechanism for the hydrolysis in acidic medium has been postulated. The observed rate constants, activation and thermodynamic parameters for the hydrolysis have been calculated. The effects of pH, molecular structure, temperature and change in percentage of water in the DMF-buffer mixture on the rate of hydrolysis have been discussed.