Rice milling is the largest agro-based industry in Sri Lanka, but workers rarely use protective gear. We tried to identify and quantify the effects of inhalation of rice husk dust on respiratory function of rice millers in Anuradhapura district, Sri Lanka. Rice millers (male:84, female:84) and controls (male:84, female:84) were matched for determinants of lung functions. Data were collected via questionnaires, physical examination and spirometry. Results showed that rice millers, irrespective of gender, had significantly lower FVC, FEV1 and PEFR (p<0.05) and increased prevalences of respiratory symptoms when compared with controls. Among millers, 42% of males and 38% of females had features of chronic respiratory disease. Exposure to dust over a few hours caused significant reductions in FVC and FEV1 in female millers. Observed deficiencies in lung functions were probably caused by occupational exposure to rice husk dust. Wearing face masks, worker education and adequate ventilation in mills are recommended.