Byssinosis has been recognized as a respiratory disorder associated with cotton dust exposure for more than two centuries. This respiratory disorder is characterized by the clinical symptoms of bronchoconstriction with work week periodicity and later by a decline in lung function over the working shift, most marked following an absence from the job. Byssinosis risk is probably influenced by length of exposure and type of mill such as textile mill, cottonseed oil crushing mill, or ginning mill. Prevalence seems not to be influenced by age, sex, or race. This study attempted to answer the question whether long-term exposure to cotton textile dust led to clinically important pulmonary functional impairment.