A novel series of 1,3,4-oxadiazole containing sulfonamide derivatives were synthesized by 5-(5-cyclohexyl-1,3,4-oxadiazol-2-yl)-2-methyl-benzenesulfonyl chloride. A good yield of intermediate with various substituted like aryl/hetero was formed. All the synthesized compounds were characterized by FT-IR, 1H NMR, 13C NMR and mass spectral studies. These compounds were evaluated for their preliminary bioassay in vitro antimicrobial activity, anti-inflammatory and anti-diabetic activities. In this series, most of the compounds have good anti-inflammatory activity. Particularly, compounds 5c, 5d and 5e showed excellent anti-inflammatory activity with IC50 values of 110, 110, and 111 μg/mL than diclofenac (157 μg/mL). The frontier orbital energy and the global reactivity descriptor were discussed for the tested compounds using RB3LYP/311G(d,p) basis set. Results revealed that the theoretical calculations of antimicrobial activity were closely related to quantum chemical parameters. KEY WORDS: 1,3,4-Oxadiazole, Sulfonamide, Antimicrobial, Anti-diabetic, Anti-inflammatory, FT, SAR Bull. Chem. Soc. Ethiop. 2019, 33(2), 307-319.DOI: https://dx.doi.org/10.4314/bcse.v33i2.1