Medicinal plants are the oldest known source for the treatment of diseases. The use of plants and plant extracts for isolation of pharmaceutical compounds has received increasing attention from researchers over the past decades. We determined the antibacterial activity of dried black lime (Citrus aurantifolia) extracts on Gram-positive and Gram-negative human pathogens, including Enterococcus faecalis, Staphylococcus aureus, methicillin-resistant Staphylococcus aureus (MRSA), Escherichia coli, Pseudomonas aeruginosa and Salmonella typhimurium by using agar well diffusion methods. Crude extracts were obtained from different organic solvents and from sterile distilled water as an aqueous solvent. Considerable antibacterial activity was observed for the methanolic extracts, particularly against E. faecalis. P. aeruginosa was the most susceptible among the Gram-negative bacteria. HPLC analysis of methanol dried lime extracts revealed a peak with a retention time of similar to that of the standard gallic acid, which is known to have potent antibacterial activity.