Abstract: The antibacterial activity of Ziziphus spina-christi leaves ethanolic and methanolic extracts were examined using agar disc diffusion method against eight bacteria (Salmonella typhi, Proteus mirabilis, Shigella dysenteriae, Escherichia coli, Klebsiella pneumoniae, Brucella melitensis, Bordetella bronshiseptica and Pseudomonas aeruginosa). These extracts had inhibitory effect at various concentrations (0.05, 0.1, 0.2, 0.3 and 0.4 g mL-1) against tested bacteria. The ethanolic extract had the highest activity (20 mm) against B. bronchiseptica while the lowest activity (7 mm) was demonstrated by the methanolic extract on K. pneumoniae. Studies on the Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) of the methanolic extract on two selected bacteria showed that the S. dysenteriae had the highest MIC (18 mg mL-1) and MBC (64 mg mL-1) values.