Back ground: textile cotton workers are at risk for occupational lung disease, includingrnbyssinosis and chronic bronchitis. Byssinosis is a respiratory disease primarily associated withrnexposure to cotton dust. Respiratory symptoms and impairments in pulmonary function arernthe major consequences of occupational exposures.rnObjective: the aim of the study was to determine the prevalence of respiratory symptoms andrnbyssinosis among production workers in cotton mills of Akaki textile factory, Addis Ababarn2006/2007.rnMethodology: a cross-sectional study in which by information on demographicrncharacteristics, cigarette smoking, occupational history and respiratory symptoms, wererncollected from February to April 2006. Four hundred seventeen production workers wererninterviewed with modified American Thoracic Society standard respiratory symptomsrnquestionnaires. FEV1, FVC and FEV1/FVC were measured using portable medicalrnspirometer. Dust concentration in the work environment was measured by the Data RAM 4rnreal time measurement of area sampling. The data entry was performed using EPI INFOrnversion 6.04d and exported to SPSS version 13.0 for analysis. The adjusted odds ratio wasrncalculated for each respiratory symptoms and byssinosis. Multivariate Logistic regressionrnanalysis was used to identify the predictors of respiratory symptoms and byssinosis and onernway analysis of variance (ANOVA) used to compare means of pulmonary function tests.rnResult: The highest prevalence of respiratory symptoms (cough 77.0%, phlegm 62.0%, chestrntightness 46.0% and dyspnea 62.0%) were found in the carding section .Workers in cardingrnsections were more likely to contract phlegm 13 times and chest tightness 8 times higherrncompared to others sections. Workers in blowing sections were seven times more likely tornhave dyspnea than other sections. The over all prevalence of chronic bronchitis was 23.0%rnand the highest found in carding section (69.2%) and the lowest in weaving section (16.2%).rnWorkers in carding section were 13 times more likely to have chronic bronchitis compared tornother sections (OR=13.4, 95% CI 3.43-52.6). The prevalence of byssinosis was 38.0%. Thernhighest found in the carding (84.6%), drawing (72.2%) and ring frame (63.0%) sections.rnWorkers in the blowing and carding areas were exposed to the high levels of cotton dust withrnmean dust levels of 32.2 mg/ m3 and 8.0 mg/ m3 respectively.rnviirnAbout 11.0% of byssinotics developed FEV1 severe chronic changes. Of the byssinoticrnworkers, 32% to 45% showed slight to moderate chronic impairment and 52.0% to 54.8% hadrnno chronic impairment.rnThis study provided important evidence indicating the strong relationship between the highrnprevalence of byssinosis and other respiratory impairments on exposure to cotton dust. Thernresults also emphasize the importance of applying a pulmonary function test to detect earlyrnexposure effects .In view of the above findings, preventive measures like controlling dust,rnusing face masks, and other measures are of supreme importance in minimizing thernprevalence of byssinosis and other respiratory disorders in textile manufacturing.