In the green synthesis, salicylaldehyde and N-(substituted)phenyl malonic acid are condensed in the presence of piperidine, a base catalyst. The antibacterial properties of some described substances were evaluated, and this clearly indicated the therapeutic relevance of addressing antimicrobial etiology. The produced coumarin compounds were tested at concentrations ranging from 25 to 100 μg/ml for their antibacterial activity against two different bacterial strains. Compound 4 demonstrated the strongest antibacterial efficacy against S. aureus. For every bacterial strain that was examined, the negative control failed to establish a zone of inhibition. Key Words: Coumarin, knoevenagel’scondensation, anti-bacterial activity