During a four-year follow-up period the indicators of work load, individual factors, and stress reactions predicting mortality, disability, and change of occupation were studied. In 1981, 6257 active workers aged 44-58 years answered a questionnaire. The study was repeated in 1985 when 1% of the subjects had died, 9% had become disabled, and 5% had changed their occupation. These changes had occurred the most often in occupations which included muscular work, poor work postures, and a poor physical environment. The highest mortality rate was observed for the male installation and auxiliary workers who had reported the presence of cardiovascular, but no musculoskeletal, disease four years earlier. The highest disability rate was well predicted by a poor index of work ability. Major diseases leading to disability included malignant tumor, coronary artery disease, congestive heart failure, rheumatoid arthritis, bronchitis or bronchial asthma, and mental disease. Work-related stress reactions were associated with both mortality and disability.