Microbial infections are currently a widespread disease in hospitals and community health centres and are a major cause of death worldwide. In pursuit of searching new antimicrobial agents, coumarin linked to thiazoles, pyridines and pyrazoles have been developed and evaluated for their antimicrobial properties against two Gram + bacteria, two Gram − bacteria as well as two fungi. Some of the prepared coumarins displayed high to moderate activity against the tested microorganisms with respect to the reference drugs. However, compound3exhibited antimicrobial effect equal to the reference drug Ciprofloxacin for Gram − baceriaEnterobacter cloacae. Compound12was found to be the most potent compound againstBacillus pumiliswith MIC of 7.69 (µmol/ml). Compounds3,4and12showed remarkable activity againstStreptococcus faecaliswith MIC of 14.34, 3.67 and 15.36 (µmol/ml), respectively. RegardingEscherichia coli, most compounds recorded high to moderate MIC values (4.73–45.46 µmol/ml). Moreover, in case ofE. cloacaecompound9was the most potent compound with MIC value of 22.76 (µmol/ml).