Conventional light microscopy using Ziehl-Neelsen (ZN) stained smears prepared directly fromrnsputum specimens is the most widely available test for diagnosis of tuberculosis (TB) inrnresource-limited settings. However, a major shortcoming of conventional microscopy is its lowrnsensitivity compared with culture. A cross-sectional study in the outpatient departments of St.rnpeterâ€™s TB specialized hospital in Addis Ababa, Ethiopia from May, 2010 to December, 2010rnwas conducted to compare the diagnostic value of the combination of bleach and light emittingrndiode fluorescent microscopy (LED-FM) against mycobacterial culture in the diagnosis ofrnpulmonary tuberculosis (PTB) Adult patients with chronic cough, weight loss, sweats , fever,rnhemoptysis, chest pain with radiographic findings without treatment or on anti-TB chemotherapyrnwere included in the study. Three consecutive sputum specimens from patients who fulfilled entryrncriteria were processed. Direct smear were prepared and stained using auramine phenol andrnZiehl Neelsen techniques. Concentrated slides using bleach were stained by auramine-phenolrnmethod with culture on MGIT media as the gold standard. Capilia TB Assay method were usedrnto identify M. tuberculosis.rnThree hundrades and fifty three sputa were processed. The sensitivity, specificity, positive andrnnegative predictive values achieved with direct fluorescent microscopy compared to culture werern59.7%, 98.3%, 94.4% and 83.6% respectively. The correlation between direct fluorescentrnmicroscopy and culture as gold standard method showed statistical significance ( 2 = 159.78, Prn< 0.001).Concentration of sputum with bleach significantly increased auramine/phenol smearrnsensitivity by 72.8%, a 13.1% incremental yield ( 2 = 197.8, P < 0.0001). A comparison ofrndirect ZN and FM smear results showed that, direct FM sensitivity was significantly higher thanrndirect ZN microscopy (59.7% vs 41.2%, difference 18.5%, 2 = 159.3, CI 30.2 â€“ 249.8,rnP