Abstract In an attempt to find new agents to fight against microbial infections, a series of coumarin-based 1, 3, 4-oxadiazol-2ylthio-N-phenyl/benzothiazolyl acetamides was synthesized starting from coumarin-3-carboxylic acid ethyl ester obtained through Knoevenagel and Pinner reaction. In vitro antimicrobial activity against several bacteria (S. aureus, B. cereus, E. coli, P. aeruginosa, K. pneumoniae, S. typhi, P. vulgaris, S. flexneri), ...