Quarry workers who are involved in stone cutting form an unorganized sector.The workers are exposed to silica dust of different concentration and particulate size. Irrespective of the particulate size of silica to which the worker is exposed, the end result is deterioration of pulmonary function. The objectives of this study were to study the deterioration of pulmonary function in quarry workers and its relation with duration of their exposure. This study was conducted in Andhra Pradesh, India, on 75 male quarry workers and 75 healthy age, gender, height, weight matched controls. The pulmonary function tests were performed in quarry workers and controls, Pulmonary functions were assessed by using computerized spirometer (Spirowin 2.0). Results were compared by unpaired student’s ‘t’ test, and correlation between duration of work and % difference in pulmonary function was done using Pearson correlation co efficient.The results showed a significant reduction in mean values of FVC, FEV1, FVC/FEV1 %, PEF, and FEF25-75% between quarry workers and their matched controls. Further, the % reduction of pulmonary function values were positively correlated with duration of their work.On comparing pulmonary functions between quarry workers and controls, it was concluded that the exposure to dust containing silica in quarry workers leadsto deterioration of pulmonary function and it is correlated with the duration of the exposure. We recommend that protection to the workers may be provided in the form of wet working, suitable ventilation ,and information about preventive measures .