Biofilm is a "growing" problem and needs effective remedial agents. Here we report novel methyl 4-((4-(4-chlorophenyl)-2,5-dioxoimidazolidin-1-yl) methyl) benzoate derivatives (5a-l) as antibiofilm and antimicrobial agents evaluated with both in silico and in vitro techniques. When it comes to Gram-positive bacterial strains like Staphylococcus aureus (MTCC 737), MRSA and Streptococcus pneumoniae (MTCC 1936), and Gram-negative bacterial strains like Pseudomonas aeruginosa (MTCC 424) and Escherichia coli (MTCC 443), the minimum inhibitory concentration (MIC), minimum biofilm inhibition concentration (MBIC), and anti-biofilm activity were measured. Out of all the compounds (5a-l), 5b and 5d showed no toxicity to mammalian cells and were equally active against various Gram-positive and Gram-negative bacteria at low concentrations (MIC: 0.1-9.5 µg/mL). Compounds 5b and 5d were also validated for the DNA gyrase inhibition potential as an antimicrobial mechanism of action in vitro. These compounds showed high level DNA gyrase inhibition potentials (IC