The basic nucleus 4-amino-5-[4-(methylsulfonyl)benzyl]-2,4-dihydro-3H-[1,2,4]-triazole-3-thione was prepared by cyclisation of potassium dithiocarbazinate with hydrazine hydrate using ethanol as solvent under reflux condition. The compound which has been synthesized successfully was subjected to addition reaction with different aldehydes to synthesize Schiff bases. The compounds were confirmed by spectroscopic methods (IR, NMR, and Mass). In order to ascertain the pharmaceutical application, the selective pharmacological screening of the derivatives was carried out according to the standard procedures. The compounds were screened for their cytotoxic activity and antimicrobial activity