_____________________________________________________________________________________________________ *Corresponding author: E-mail: adamomer4@gmail.com; South Asian Research Journal of Natural Products 1(3): 1-6, 2018; Article no.SARJNP.44615 Antimicrobial Potential and Phytochemical Screening of Eucalyptus camaldulensis and Eucalyptus microtheca Leaves Extracts Omer Adam Omer Ishag 1* , Ibrahim Yaagoub Erwa 1 , Mohamed A. Diriye 1 , Ama Almouchakara Mamane Lawane 1 , Hamza Mohamed Ahmed 1 , Fatimah Ali Ahmed 1 , Shema Elnour Mergani 1 , Alla Elamin 1 and Awadalla B. Omer 1 1 Department of Applied and Industrial Chemistry, Faculty of Pure and Applied Sciences, International University of Africa, P.O. Box 2469 Khartoum, Sudan. Authors’ contributions This work was carried out in collaboration between all authors. All authors read and approved the final manuscript. Article Information DOI: 10.9734/SARJNP/2018/44615 Editor(s): (1) Dr. MVNL Chaitanya, Associate Professor, Department of Pharmacognsy and Phytopharmacy , Guru Nanak School of Pharmacy, Hyderabad, India. (2) Dr. Prasong Srihanam, Professor, Department of Chemistry, Faculty of Science, Mahasarakham University, Thailand. (3) Dr. Elmarie Van Der Watt, Department of Soil, Crop and Climate Sciences, University of the Free State, South Africa. Reviewers: (1) R. Dhivya, Nirmala College for Women, India. (2) Dalia Goldhaber, Leiden University, The Netherlands. Complete Peer review History: http://www.sciencedomain.org/review-history/27144 Received 12 August 2018 Accepted 25 October 2018 Published 10 November 2018 ABSTRACT Aims: The aim of this study is to investigate the phytochemical constituents and antimicrobial activity of the leaves extracts of Eucalyptus camaldulensis and Eucalyptus microtheca. Study Design: Extraction of E. camaldulensis and E. microtheca leaves using five solvents of different polarities, and screening their phytochemical constituents and antimicrobial activity against five microorganisms. Place and Duration of Study: Industrial chemistry and microbiology Departments, International University of Africa, Khartoum – Sudan, January 2017. Methodology: The leaves of E. camaldulensis and E. microtheca were extracted using water, ethanol, chloroform, ethyl acetate and petroleum ether; the extracts were used for phytochemical screening. Five concentrations (100, 50, 25, 12.5 and 6.25 mg/mL) of each extracts prepared and Original Research Article