Abstract: The purposes of this study was to measurement cotton dust levels in air workplace, Prevalence of respiratory symptoms and determine of changes in Peak Expiratory Flow Rate (PEFR) before and after during workday among textile workers. This study was done among 31 workers carding and blowing rooms. Using a short questionnaire for demographic characteristics, medical record were collected in a modified questionnaire of Occupational Safety and Health Administration (OSHA) and 12 air samples were collected of work area. The PEFR was measured with a peak flow meter. The mean cotton dust levels in carding and blowing rooms were 0.39±0.03 and 0.20±0.01 mg m-3, respectively. The mean age and year’s employment were 45±7.97 and 12.5±6.28, respectively. Thirty three percent of the workers were smoking. The prevalence of respiratory symptoms increased with age and employment years and there were found significantly between age and employment years with cough, phlegm, dyspnea (p<0.05, 0.05, 0.05, respectively). The mean PEFR before and after during workday were 362.9±147.8 and 305.8±147.5, respectively and subjects had found significantly (p<0.0001). The decline in PEFR was significantly associated with years employment (p<0.05), whereas with age and cotton dust levels were found to be non significant. One explanation for the lack of age and cotton dust levels effects in workers may be due to the low number of subjects and samples, respectively. Technological improvement has resulted in reduction of cotton dust exposure levels and respiratory symptoms.