BACKGROUND: Tuberculosis is a communicable disease caused by infection withrnMycobacterium tuberculosis complex group and infects almost one third part of the worldrnpopulation and kills around two million people worldwide each year. Much attention has recentlyrnbeen paid to the problem of smear-negative pulmonary tuberculosis. Quite appropriately, therndiscussion has focused on low-income countries, home to the vast majority of individuals withrntuberculosis and HIV and where the ability to culture diagnostic specimens may be lacking. Inrnparticular, smear-negative pulmonary TB (SNPTB) has become an increasing important clinicalrnand public health problem, especially in areas that are affected by the dual infection ofrntuberculosis and Human immunodeficiency Virus, such as sub-Saharan Africa includingrnEthiopia.rnOBJECTIVE: The aim of the study is to determine the prevalence of smear negative pulmonaryrntuberculosis using standard culture methods and clinical algorithm among PTB suspectedrnpatients at Adama Referral Hospital, Adama, Ethiopia .rnMETHODS: A cross sectional study was conducted among suspected pulmonary tuberculosisrnpatients (age >18 years old) visiting at Adama referral hospital in Eastern oromia Region fromrnJune 2013 to December 2013. The study subjects were all smear negative pulmonaryrntuberculosis patients and a consecutive sampling technique was used. A sputum sample wasrncollected from patients who had smear negative result by Zihel Neelson method/technique. Allrnsmear negative pooled sputum samples was processed for culture using conventionalrnLowenstein-Jensen solid medium at the Adama regional laboratory. Descriptive statistics wasrncomputed. P < 0.05 will be statistically significance and multivariate logistic regression will bernused for analysis of the result.rnRESULTS: Of 232 AFB smear-negative patients, 130(56 %) were males. The mean age of thernrespondents was 40.2 ranging from 19 to 77 years old. Of 232 AFB smear-negative patients, 28rn(12.1) were MTB culture positive. Among adults PTB suspected patients; smear-negative TBrnculture positive was less prevalent (10.7%) in age group 41-50 years. Majority (71.4%) of smear-rnnegative TB culture positive was observed in malernThe majority of patients came with a combination of symptoms and the entire patient hadrnchronic cough more than two weeks. Of the study participants, 116(50.0%) had abnormal chestrnx-ray finding.rnThe binary- logistic regression identified that Productive cough (OR (95%CI)= 0.82(0.81-0.91)),rnHaemoptysis (OR (95%CI)= 2.43(1.04-5.68)), night sweats (OR (95%CI)= 6.85(2.00-23.39)),rnUnexplained weight loss (OR (95%CI)= 3.44(1.53-7.72)), the presence of typical X-ray Findingsrn(OR (95%CI)= 2.81(1.18-6.68)), and being HIV patients or positive(OR (95%CI)=4.92(2.1-rn11.5)) were independently associated with confirmed SNPTB. But in Multivariate regressionrnanalysis, Productive cough (OR (95%CI)= 0.82(0.81-0.91)), night sweats (OR (95%CI)=rn8.27(2.27-30.1)), and being HIV patients or positive(OR (4.16(1.45-11.96)) were significantlyrnassociated with confirmed SNPTB.