Compounds 2 were synthesised via the reaction of 4-amino-5-thiophen-2-yl-methyl-2,4-dihydro-[1,2,4]triazol- 3-one (1) with aldehydes. Compounds 3 and 4 were obtained from compounds 2 with bromo acetophenone and ethyl bromoacetate, respectively. The synthesis of compounds 2, 3, and 4 and crystal structure of compound 2a are being reported. The molecular structures were identified by IR, (1) H-NMR, (13)C-NMR, MS, and elemental analyses. Compound 2a crystallises in the monoclinic P 21/n space group, with a = 6.565(5) angstrom, b = 18.278(5) angstrom, c = 13.8166(18) angstrom, beta = 96.227(5)., V = 1553.6(14) angstrom 3, Z = 4. The newly compounds synthesised were screened for their antibacterial and antifungal properties. Among the compounds, 4d showed antimicrobial activity against Candida albicans ATCC 60193 and Candida tropicalis ATCC 13803.