Silicosis is the most common occupational disease notified in Hong Kong. Annually, up to 200 cases--mostly from the construction industry--are reported. To elucidate the personal and behavioural risk factors for silicosis, we studied 215 silicosis patients in the construction industry and 173 controls from 1990 to 1992. We investigated occupational exposure to dust, work practice, education, vocational and safety training, work experience and personal habits (cigarette smoking, alcohol intake). No formal education, no vocational and safety training, current and past smoking, and the use of dust masks were found to be significant risk factors. Because of selection bias in the choice of controls in this study, risk factors identified in the logistic regression model have to be interpreted with caution. In addition to dust suppression on construction sites, on-the-job safety, health training and health maintenance programmes should be provided to construction workers. Health education should be aimed at increasing worker awareness of the danger of fibrogenic dusts, encourage the proper use and maintenance of effective personal protective equipment, implement dust supression measures, and discourage smoking.