The aim of this work was to investigate the efficie ncy of N 1 –(2-Benzylidene-imino-5'- methylene)-1',3',4'-thiadiazole]-2-methyl-benzimida zoles, 4(a-n) ; N '1 -[2 ' -{2-Substituted- Phenyl-1,3-thiazolidin-4-one}-5 ' -methylene-1',3',4'-thiadiazole]-2-methyl-benzimida zoles, (a- n) and N 1 -[2 ' -{2-substituted-phenyl-5-substituted-benzylidene-1, 3-thiazolidine-4-one}-5 ' - methylene-1',3',4'-thiadiazole] -2-methyl-benzimida zoles, 6(a-n) for the synthesis by conventional and greenar approach methods in terms of yield and reaction time along with antimicrobial activity against Bacillus subtilis, Escherichia coli. Klebsiella pne umoniae and Streptococcus aureus bacteria and Aspergillus niger, Aspergillus flavus, Fusarium oxi sporium and Trichoderma viride fungi in vitro at 50 and 100 ppm concentrations . Some of the compounds displayed pronounced biological activity. The struc tures of all the new compounds were established on the basis of elemental analysis and spectral data (IR, 1HNMR and mass).