Dust can be produced by almost all production processes in Portland cement factory. Dust exposure potentially can affect respiratory function.In this study we assessed effect of cement dust exposure on respiratory function in a cement production factory in Chittorgarh Rajasthan. A respiratory symptoms questionnaire was completed and pulmonary function tests were carried out on 55 exposed and 24 non exposed workers at a cement factory. Additionally, respirable dust level was determined by the gravimetric method. X-ray fluorescence (XRF) technique was performed to determine the silica phases and the SiO2 contents of the bulk samples. The arithmetic means of personal respirable dust were 24.22 mg/m3 in the crushing, 21 mg/m3 in the packing, 4.3 mg/m3 in the cement mill, 4.2 mg/m3 in the kiln and 4.9 mg/m3 in the maintenance that were higher than threshold limit value of the American Conference of Governmental Industrial Hygienists which is 4 mg/m3. This value in the unexposed group was 0.81 mg/m3. In this study cough, sputum, wheezing and dyspnea were more prevalent among exposed subjects. Exposed workers compared to the unexposed group showed significant reduction in Forced Expiratory Volume in one second ,Forced Vital Capacity , and Forced Expiratory Flow between 20% and 80 % of the Forced Vital Capacity (P<0.05). It can be concluded that in our study there was close and direct association between cement dust exposure and functional impairment among the cement factory workers