Resistances to current antibacterial drugs are growing global concerns. Traditional medicine is a potential source of new antibacterial. The main purpose of this study firstly, it is to find the chemical compounds in the Citrullus colocynthis Schard fruits leaves and roots , secondly, to evaluate the antibacterial activity of aqueous and hydromethanolic extract of the different parts. Phytochemical screening revealed the presence of some active substances flavonoids, saponins and steroid, to express the desired activities. Aqeous and hydromethanolic extract of fruit, leaves and root of Citrullus colocynthis Schard are examined for their antibacterial potentialities against gram positive and gram negative bacteria, All extracts show activity against all bacteria strains, the highest MIC were obtained from the roots hydromethanolic extract with 5.6mg/ml Against Klebsiella pneumonia; Listeria monocytogen and Pseudomonas aerugenosa.

Keywords: Citrullus colocynthis Schard; Phytochemical screening; antibacterial; extract