This book is about antibacterial and antifungal activities of Ziziphus spina-Christi(L.) petroleum ether, chloroform, methanol and aqueous extracts of its different parts fruits, leaves, seeds and stems. They were screened for their antimicrobial activity against six standard pathogenic bacteria and two pathogenic fungi. The minimum inhibitory concentrations (MIC) of the most active extracted parts were determined against the standard pathogenic bacteria and fungi using agar cup diffusion method.