Background: In Ethiopia, the main tool used to diagnosis pulmonary tuberculosis is Ziehl-rnNeelsen microscopy. The emergence of drug-resistant forms of tuberculosis which needs morernresources to detect, to successfully treat and effectively reduce the burden is among the toprnchallenges in the country. Tuberculosis case detection among vulnerable population groupsrnincluding children, HIV positives and other high risk groups remains low due to insensitiverndiagnostic tools. Due to its low sensitivity, Ziehl-Neelsen microscopy does not detect all positivernTB cases among TB suspects; as a result tuberculosis transmission by false negative casesrnincreases. Therefore, there is a need to assess the incremental value of new diagnostic tool likernXpert MTB/RIF assay and Light Emitted Diode Fluorescent microscopy for tuberculosisrndetection in our setting.rnObjective of the study: To determine the performance of Xpert MTB/RIF assay in comparisonrnwith Light Emitted Diode Fluorescent microscopy and Ziehl-Neelsen smear microscopy forrndetection of Mycobacterium Tuberculosis in sputum samples in Addis Ababa.rnMethods and Materials: A prospective cross-sectional study from December, 2013 to April,rn2014 was conducted in AAHRL to compare the performance of light emitting diode fluorescentrnmicroscopy (LED-FM), Xpert MTB/RIF assay and Ziehl-Neelsen(ZN) smear microscopy in therndiagnosis of pulmonary tuberculosis (PTB) Adult patients. LJ culture media was used as the goldrnstandard for sub-samples. All data was entered into an excel spreadsheet, then transfer andrnanalyzed using SPSS version 20. Descriptive statistics was performed and data presented inrntables. McNamaraâ€™s and Kappa statistics was used for proportion and the percent agreementrnanalysis.rnResults: A total of 358 pulmonary tuberculosis and MDR-TB (Multi drug resistancerntuberculosis) suspected patients were enrolled from December, 2013 to April, 2014 in AddisrnAbaba Health research and Laboratory with mainly young adults of median age 30.5. Afterrnexcluding 8 samples that were invalid by Xpert MTB/RIF assay 350 samples were analyzedrnstatistically and The percent agreement between Light Emitted Diode Fluorescent microscopyrnand Ziehl-Neelsen smear microscopy, Xpert MTB/RIF assay and Light Emitted DiodernFluorescent microscopy, Xpert MTB/RIF assay and Ziehl-Neelsen smear microscopy for MTBrndetection showed that k=75%(95%CI,67% to 81%), p