Background: Ramazzini described a peculiar form of asthma among those who card flax and hemp. Byssinosis is the most common disease affecting the cotton textile workers; also symptoms like mill fever, weaver’s cough.1 Cotton workers are at risk for occupational lung disease, including byssinosis and chronic bronchitis3. The present study was done to find out the effect of short term exposure, long term exposure to cotton dust in cotton mill workers & control group. Suggest precautions to prevent this. Objective: 1) To assess the impact of cotton dust exposure on respiratory health & pulmonary function among cotton mill workers. 2) To understand and compare the effect of short term and long term exposure groups to cotton dust with control group on pulmonary function tests in cotton mill workers. 3) To study the severity of respiratory symptoms occur in mill workers after short term and long term exposure to cotton dust and compare with control group. Methodology: The study is approved by institutional ethical committee and written consent of participant has been taken. In this study, 2 study groups of fifty workers exposed for short term duration exposure, for long term duration exposure each and third group of fifty people not exposed to cotton dust (control group) were examined for PFTs of age 25-50 years. PFTs were carried out using spirometer. Results: The present study found that there is statistically significant difference in PFTs between the short term exposed group, long term exposed group and control group of 25-50 years’ age. The difference in symptoms were more in long term exposure group than in short term exposure group and absent in control. Also there is statistically significant difference in PFTs amongst all. Discussion & conclusion: The results of the present study helped us to understand and compare the short-term, long term exposure group and control group better and suggest workers to take precautions to avoid more subtle effects that can occur.