The rising issue of antibiotic resistance has made the search for new antimicrobial agents a global priority. Plant leaves, abundant in bioactive compounds, are a valuable source of antimicrobial potential. Secondary metabolites such as phenols, flavonoids, terpenes, and alkaloids present in plant leaves have shown significant inhibitory effects against various pathogenic bacteria. This chapter presents the experimental principles, material preparation, procedures, and precautions for evaluating the antibacterial potential of leaf extracts against human pathogenic bacteria using the microdilution method. The aim is to systematically assess the antibacterial activity of plant leaf extracts against common human pathogens and identify plant species with promising antimicrobial properties. These findings lay the groundwork for developing natural antimicrobial agents and provide direction for future research and development of natural antimicrobial products.